feat(stats): reading statistics — session capture wired + /stats page + widget + per-book card

The design parked in the handoff (multi-tier stats off reading_history;
bookorbit-style in data, not looks) is in. The real prerequisite work
was data: reading_history existed but NOTHING wrote to it — the whole
stats feature was sitting on an empty table.

- CAPTURE (no client changes, no repo-boundary crossings): every
  successful progress write through SaveProgress (KOReader + app + web
  + Kobo + offline queue — the one chokepoint) now records one
  reading_history session row: span = the interval since the PREVIOUS
  write instant, pages = positive page delta when both sides know the
  page index, marker rows for first contact. Spans over 2h are kept as
  zero-second markers (overnight suspend→resume, offline flushes must
  not inflate totals) — the honest 'sync cadence, not a stopwatch'
  caveat stays. device_id only when a REAL device row matches (the
  web/app progress path historically stuffs the USER id into DeviceID
  — probe instead of trusting it; FK violation would silently drop
  every capture). Source preserved in device_metadata.

- API: /api/stats/summary?range=7|30|90|year (totals, zero-filled
  daily arrays, streaks, most-active day/weekday, top books, library
  breakdown — one call), /api/stats/this-week (widget: rolling 7d vs
  previous + streak), /api/stats/books/:id (lifetime + recent
  sessions). All bucketed in the user's timezone; finished ≡ any push
  ≥0.995; visible-library lens enforced at source. Legacy
  /api/analytics/* kept untouched. Range windows anchor end-of-day to
  the START of today (blasting the clock time into tomorrow resolved
  'today' a calendar day late — found by the streak test).

- /stats page (sidebar Stats between Progress and Devices, previously
  /analytics was an orphan): range selector, five stat cards, two
  Chart.js v4 charts (daily minutes bar, pages/day line — chunked via
  dynamic import so main.js stays untouched), per-library breakdown,
  most-read list, empty-state explainer. /analytics now 301s to /stats.
  The orphaned analytics.templ + analytics.ts removed (their containers
  and the page JSON never matched; the page was astub).

- Dashboard 'This Week' widget (server-rendered, suppressed on service
  failure) and the book detail 'Your Reading Stats' card (lifetime
  totals of the viewer's own sessions) complete the tiers: per-user
  default, per-library breakdown inline, per-book on the page,
  per-system/admin aggregate parked as before.

Tests: statistics_test.go (capture semantics at the chokepoint,
tz/day buckets, zero-fill, streak math, finished detection, range
validation, auth gate, widget, per-book lifetime). Full suite PASS.

internal/database/querier.go

@@ -153,6 +153,10 @@ type Querier interface {
 	DeleteUnlinkedBook(ctx context.Context, id pgtype.UUID) error
 	DeleteUser(ctx context.Context, id pgtype.UUID) error
 	DeleteUserSystemCollection(ctx context.Context, arg DeleteUserSystemCollectionParams) error
+	// Device existence probe for capture: the web/app progress paths
+	// historically stuff the user id into DeviceID (it only fed a broadcast
+	// label before stats); a capture row must only reference a REAL device.
+	DeviceExistsForUser(ctx context.Context, arg DeviceExistsForUserParams) (bool, error)
 	// Find content-duplicate groups (same library + SHA-256, more than one row)
 	FindHashConflictGroups(ctx context.Context) ([]FindHashConflictGroupsRow, error)
 	GenerateKoboEntitlementId(ctx context.Context) (interface{}, error)
@@ -165,6 +169,8 @@ type Querier interface {
 	GetAllSystemSettings(ctx context.Context) ([]GetAllSystemSettingsRow, error)
 	GetAllSystemSettingsFull(ctx context.Context) ([]SystemSettings, error)
 	GetAnnotationsForBook(ctx context.Context, arg GetAnnotationsForBookParams) ([]GetAnnotationsForBookRow, error)
+	// Lifetime session rows for ONE book (the book-detail stats card).
+	GetBookReadingSessions(ctx context.Context, arg GetBookReadingSessionsParams) ([]GetBookReadingSessionsRow, error)
 	GetBooksByTag(ctx context.Context, arg GetBooksByTagParams) ([]MediaItems, error)
 	// Get collection
 	GetCollection(ctx context.Context, id pgtype.UUID) (Collections, error)
@@ -338,6 +344,8 @@ type Querier interface {
 	GetSystemSettingFull(ctx context.Context, settingKey string) (SystemSettings, error)
 	GetSystemTimezone(ctx context.Context) (string, error)
 	GetTombstonedAnnotationsForBook(ctx context.Context, arg GetTombstonedAnnotationsForBookParams) ([]GetTombstonedAnnotationsForBookRow, error)
+	// Most-read books for a range (minutes), for the top list.
+	GetTopBooksByMinutes(ctx context.Context, arg GetTopBooksByMinutesParams) ([]GetTopBooksByMinutesRow, error)
 	// Get universal progress for a book
 	GetUniversalProgress(ctx context.Context, arg GetUniversalProgressParams) (GetUniversalProgressRow, error)
 	// Get unlinked book by ContentId
@@ -354,12 +362,27 @@ type Querier interface {
 	// Get user device usage statistics
 	GetUserDeviceUsage(ctx context.Context, userID pgtype.UUID) ([]GetUserDeviceUsageRow, error)
 	GetUserForLogin(ctx context.Context, email string) (GetUserForLoginRow, error)
+	// Per-library aggregation for the same range.
+	GetUserLibraryBreakdown(ctx context.Context, arg GetUserLibraryBreakdownParams) ([]GetUserLibraryBreakdownRow, error)
 	GetUserMediaItemsForSync(ctx context.Context, userID pgtype.UUID) ([]GetUserMediaItemsForSyncRow, error)
 	GetUserPasswordHash(ctx context.Context, id pgtype.UUID) (string, error)
 	GetUserProgressForBooks(ctx context.Context, arg GetUserProgressForBooksParams) ([]GetUserProgressForBooksRow, error)
+	// Distinct ACTIVE days (any captured session) bucketed in the user's
+	// timezone — the streak calendar. Scoped to a long look-back so the
+	// "longest streak" and a current streak longer than the selected range
+	// are both real.
+	GetUserReadingActiveDays(ctx context.Context, arg GetUserReadingActiveDaysParams) ([]string, error)
 	// Analytics queries
 	// Get user reading history for analytics
 	GetUserReadingHistory(ctx context.Context, arg GetUserReadingHistoryParams) ([]GetUserReadingHistoryRow, error)
+	// STATISTICS (reading sessions) — time spent, pages, streaks, breakdowns.
+	// Every stats query scopes to the requesting user's VISIBLE libraries
+	// (family lens at the source) and single scan of reading_history.
+	// Full session rows for a range (summary math runs in Go: tz buckets,
+	// streaks, finished-book detection). The bucket/range key is the session
+	// END instant (the push time; NULL falls back to created_at) — the same
+	// value the capture stamps every write with.
+	GetUserReadingSessionsRange(ctx context.Context, arg GetUserReadingSessionsRangeParams) ([]GetUserReadingSessionsRangeRow, error)
 	GetUserVisibleLibraries(ctx context.Context, userID pgtype.UUID) ([]GetUserVisibleLibrariesRow, error)
 	GetVisibleLibraryMediaCounts(ctx context.Context, userID pgtype.UUID) ([]GetVisibleLibraryMediaCountsRow, error)
 	// Smart ("dynamic") collections: rules are evaluated LIVE at render, so

internal/database/queries.sql.go

@@ -2389,6 +2389,28 @@ func (q *Queries) DeleteUserSystemCollection(ctx context.Context, arg DeleteUser
 	return err
 }
 
+const DeviceExistsForUser = `-- name: DeviceExistsForUser :one
+SELECT EXISTS(
+    SELECT 1 FROM devices
+    WHERE id = $1 AND user_id = $2
+) AS has_device
+`
+
+type DeviceExistsForUserParams struct {
+	DeviceID pgtype.UUID `db:"device_id" json:"device_id"`
+	UserID   pgtype.UUID `db:"user_id" json:"user_id"`
+}
+
+// Device existence probe for capture: the web/app progress paths
+// historically stuff the user id into DeviceID (it only fed a broadcast
+// label before stats); a capture row must only reference a REAL device.
+func (q *Queries) DeviceExistsForUser(ctx context.Context, arg DeviceExistsForUserParams) (bool, error) {
+	row := q.db.QueryRow(ctx, DeviceExistsForUser, arg.DeviceID, arg.UserID)
+	var has_device bool
+	err := row.Scan(&has_device)
+	return has_device, err
+}
+
 const FindHashConflictGroups = `-- name: FindHashConflictGroups :many
 SELECT library_id, file_sha256, COUNT(*) AS dup_count
 FROM media_items
@@ -2726,6 +2748,65 @@ func (q *Queries) GetAnnotationsForBook(ctx context.Context, arg GetAnnotationsF
 	return items, nil
 }
 
+const GetBookReadingSessions = `-- name: GetBookReadingSessions :many
+SELECT
+    rh.id, rh.device_id, rh.progress_percentage,
+    rh.reading_session_start, rh.reading_session_end,
+    rh.pages_read, rh.time_spent_seconds, rh.device_metadata, rh.created_at
+FROM reading_history rh
+WHERE rh.user_id = $1
+  AND rh.media_item_id = $2
+ORDER BY rh.created_at ASC
+`
+
+type GetBookReadingSessionsParams struct {
+	UserID      pgtype.UUID `db:"user_id" json:"user_id"`
+	MediaItemID pgtype.UUID `db:"media_item_id" json:"media_item_id"`
+}
+
+type GetBookReadingSessionsRow struct {
+	ID                  pgtype.UUID        `db:"id" json:"id"`
+	DeviceID            pgtype.UUID        `db:"device_id" json:"device_id"`
+	ProgressPercentage  pgtype.Float8      `db:"progress_percentage" json:"progress_percentage"`
+	ReadingSessionStart pgtype.Timestamptz `db:"reading_session_start" json:"reading_session_start"`
+	ReadingSessionEnd   pgtype.Timestamptz `db:"reading_session_end" json:"reading_session_end"`
+	PagesRead           pgtype.Int4        `db:"pages_read" json:"pages_read"`
+	TimeSpentSeconds    pgtype.Int4        `db:"time_spent_seconds" json:"time_spent_seconds"`
+	DeviceMetadata      []byte             `db:"device_metadata" json:"device_metadata"`
+	CreatedAt           pgtype.Timestamptz `db:"created_at" json:"created_at"`
+}
+
+// Lifetime session rows for ONE book (the book-detail stats card).
+func (q *Queries) GetBookReadingSessions(ctx context.Context, arg GetBookReadingSessionsParams) ([]GetBookReadingSessionsRow, error) {
+	rows, err := q.db.Query(ctx, GetBookReadingSessions, arg.UserID, arg.MediaItemID)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+	items := []GetBookReadingSessionsRow{}
+	for rows.Next() {
+		var i GetBookReadingSessionsRow
+		if err := rows.Scan(
+			&i.ID,
+			&i.DeviceID,
+			&i.ProgressPercentage,
+			&i.ReadingSessionStart,
+			&i.ReadingSessionEnd,
+			&i.PagesRead,
+			&i.TimeSpentSeconds,
+			&i.DeviceMetadata,
+			&i.CreatedAt,
+		); err != nil {
+			return nil, err
+		}
+		items = append(items, i)
+	}
+	if err := rows.Err(); err != nil {
+		return nil, err
+	}
+	return items, nil
+}
+
 const GetBooksByTag = `-- name: GetBooksByTag :many
 SELECT id, library_id, title, author, isbn, description, file_path, file_size, mime_type, cover_image_path, series, series_number, tags, asin, date_published, publisher, contributors, language, edition, page_count, genre, copyright_year, goodreads_id, openlibrary_id, google_books_id, added_by_admin_id, created_at, imported_at, updated_at, format_group, format_mimetype, is_reflowable, has_fixed_layout, total_characters, chapter_count, entitlement_id, revision_number, kobo_content_id, kobo_metadata, manga_type, reading_direction, series_count, volume, imprint, age_rating, web_url, story_arc, is_black_and_white, metadata_notes, community_rating, alternate_info, scan_information, summary, metadata_overrides, missing_scan_count, archived_at, chapter_metadata, library_type_name, tags_search, contributors_search, file_sha256, opf_identifier, opf_uuid, hash_confidence FROM media_items
 WHERE library_id = $1 AND tags @> ARRAY[$2::text]
@@ -7674,6 +7755,85 @@ func (q *Queries) GetTombstonedAnnotationsForBook(ctx context.Context, arg GetTo
 	return items, nil
 }
 
+const GetTopBooksByMinutes = `-- name: GetTopBooksByMinutes :many
+SELECT
+    mi.id::uuid AS media_item_id,
+    mi.title,
+    mi.author,
+    mi.library_id,
+    mi.cover_image_path,
+    SUM(COALESCE(rh.time_spent_seconds, 0))::int AS total_seconds,
+    SUM(COALESCE(rh.pages_read, 0))::int AS total_pages,
+    COUNT(*)::int AS session_count,
+    MAX(rh.created_at) AS last_read
+FROM reading_history rh
+JOIN media_items mi ON mi.id = rh.media_item_id
+WHERE rh.user_id = $1
+  AND COALESCE(rh.reading_session_end, rh.created_at) >= $2
+  AND COALESCE(rh.reading_session_end, rh.created_at) <= $3
+  AND ($4::uuid[] IS NULL OR mi.library_id = ANY($4::uuid[]))
+GROUP BY mi.id, mi.title, mi.author, mi.library_id, mi.cover_image_path
+ORDER BY total_seconds DESC
+LIMIT $5
+`
+
+type GetTopBooksByMinutesParams struct {
+	UserID            pgtype.UUID        `db:"user_id" json:"user_id"`
+	StartTime         pgtype.Timestamptz `db:"start_time" json:"start_time"`
+	EndTime           pgtype.Timestamptz `db:"end_time" json:"end_time"`
+	VisibleLibraryIds []pgtype.UUID      `db:"visible_library_ids" json:"visible_library_ids"`
+	Limit             int32              `db:"limit" json:"limit"`
+}
+
+type GetTopBooksByMinutesRow struct {
+	MediaItemID    pgtype.UUID `db:"media_item_id" json:"media_item_id"`
+	Title          string      `db:"title" json:"title"`
+	Author         pgtype.Text `db:"author" json:"author"`
+	LibraryID      pgtype.UUID `db:"library_id" json:"library_id"`
+	CoverImagePath pgtype.Text `db:"cover_image_path" json:"cover_image_path"`
+	TotalSeconds   int32       `db:"total_seconds" json:"total_seconds"`
+	TotalPages     int32       `db:"total_pages" json:"total_pages"`
+	SessionCount   int32       `db:"session_count" json:"session_count"`
+	LastRead       interface{} `db:"last_read" json:"last_read"`
+}
+
+// Most-read books for a range (minutes), for the top list.
+func (q *Queries) GetTopBooksByMinutes(ctx context.Context, arg GetTopBooksByMinutesParams) ([]GetTopBooksByMinutesRow, error) {
+	rows, err := q.db.Query(ctx, GetTopBooksByMinutes,
+		arg.UserID,
+		arg.StartTime,
+		arg.EndTime,
+		arg.VisibleLibraryIds,
+		arg.Limit,
+	)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+	items := []GetTopBooksByMinutesRow{}
+	for rows.Next() {
+		var i GetTopBooksByMinutesRow
+		if err := rows.Scan(
+			&i.MediaItemID,
+			&i.Title,
+			&i.Author,
+			&i.LibraryID,
+			&i.CoverImagePath,
+			&i.TotalSeconds,
+			&i.TotalPages,
+			&i.SessionCount,
+			&i.LastRead,
+		); err != nil {
+			return nil, err
+		}
+		items = append(items, i)
+	}
+	if err := rows.Err(); err != nil {
+		return nil, err
+	}
+	return items, nil
+}
+
 const GetUniversalProgress = `-- name: GetUniversalProgress :one
 SELECT
     rp.id,
@@ -8191,6 +8351,74 @@ func (q *Queries) GetUserForLogin(ctx context.Context, email string) (GetUserFor
 	return i, err
 }
 
+const GetUserLibraryBreakdown = `-- name: GetUserLibraryBreakdown :many
+SELECT
+    l.id::uuid AS library_id,
+    l.name,
+    COUNT(*)::int AS session_count,
+    SUM(COALESCE(rh.time_spent_seconds, 0))::int AS total_seconds,
+    SUM(COALESCE(rh.pages_read, 0))::int AS total_pages,
+    COUNT(DISTINCT rh.media_item_id)::int AS book_count
+FROM reading_history rh
+JOIN media_items mi ON mi.id = rh.media_item_id
+JOIN libraries l ON l.id = mi.library_id
+WHERE rh.user_id = $1
+  AND COALESCE(rh.reading_session_end, rh.created_at) >= $2
+  AND COALESCE(rh.reading_session_end, rh.created_at) <= $3
+  AND ($4::uuid[] IS NULL OR mi.library_id = ANY($4::uuid[]))
+GROUP BY l.id, l.name
+ORDER BY total_seconds DESC
+`
+
+type GetUserLibraryBreakdownParams struct {
+	UserID            pgtype.UUID        `db:"user_id" json:"user_id"`
+	StartTime         pgtype.Timestamptz `db:"start_time" json:"start_time"`
+	EndTime           pgtype.Timestamptz `db:"end_time" json:"end_time"`
+	VisibleLibraryIds []pgtype.UUID      `db:"visible_library_ids" json:"visible_library_ids"`
+}
+
+type GetUserLibraryBreakdownRow struct {
+	LibraryID    pgtype.UUID `db:"library_id" json:"library_id"`
+	Name         string      `db:"name" json:"name"`
+	SessionCount int32       `db:"session_count" json:"session_count"`
+	TotalSeconds int32       `db:"total_seconds" json:"total_seconds"`
+	TotalPages   int32       `db:"total_pages" json:"total_pages"`
+	BookCount    int32       `db:"book_count" json:"book_count"`
+}
+
+// Per-library aggregation for the same range.
+func (q *Queries) GetUserLibraryBreakdown(ctx context.Context, arg GetUserLibraryBreakdownParams) ([]GetUserLibraryBreakdownRow, error) {
+	rows, err := q.db.Query(ctx, GetUserLibraryBreakdown,
+		arg.UserID,
+		arg.StartTime,
+		arg.EndTime,
+		arg.VisibleLibraryIds,
+	)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+	items := []GetUserLibraryBreakdownRow{}
+	for rows.Next() {
+		var i GetUserLibraryBreakdownRow
+		if err := rows.Scan(
+			&i.LibraryID,
+			&i.Name,
+			&i.SessionCount,
+			&i.TotalSeconds,
+			&i.TotalPages,
+			&i.BookCount,
+		); err != nil {
+			return nil, err
+		}
+		items = append(items, i)
+	}
+	if err := rows.Err(); err != nil {
+		return nil, err
+	}
+	return items, nil
+}
+
 const GetUserMediaItemsForSync = `-- name: GetUserMediaItemsForSync :many
 SELECT
     mi.id,
@@ -8358,6 +8586,52 @@ func (q *Queries) GetUserProgressForBooks(ctx context.Context, arg GetUserProgre
 	return items, nil
 }
 
+const GetUserReadingActiveDays = `-- name: GetUserReadingActiveDays :many
+SELECT DISTINCT (COALESCE(rh.reading_session_end, rh.created_at) AT TIME ZONE $1::text)::date::text AS day
+FROM reading_history rh
+JOIN media_items mi ON mi.id = rh.media_item_id
+WHERE rh.user_id = $2
+  AND COALESCE(rh.reading_session_end, rh.created_at) >= $3
+  AND ($4::uuid[] IS NULL OR mi.library_id = ANY($4::uuid[]))
+ORDER BY day ASC
+`
+
+type GetUserReadingActiveDaysParams struct {
+	Tz                string             `db:"tz" json:"tz"`
+	UserID            pgtype.UUID        `db:"user_id" json:"user_id"`
+	StartTime         pgtype.Timestamptz `db:"start_time" json:"start_time"`
+	VisibleLibraryIds []pgtype.UUID      `db:"visible_library_ids" json:"visible_library_ids"`
+}
+
+// Distinct ACTIVE days (any captured session) bucketed in the user's
+// timezone — the streak calendar. Scoped to a long look-back so the
+// "longest streak" and a current streak longer than the selected range
+// are both real.
+func (q *Queries) GetUserReadingActiveDays(ctx context.Context, arg GetUserReadingActiveDaysParams) ([]string, error) {
+	rows, err := q.db.Query(ctx, GetUserReadingActiveDays,
+		arg.Tz,
+		arg.UserID,
+		arg.StartTime,
+		arg.VisibleLibraryIds,
+	)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+	items := []string{}
+	for rows.Next() {
+		var day string
+		if err := rows.Scan(&day); err != nil {
+			return nil, err
+		}
+		items = append(items, day)
+	}
+	if err := rows.Err(); err != nil {
+		return nil, err
+	}
+	return items, nil
+}
+
 const GetUserReadingHistory = `-- name: GetUserReadingHistory :many
 
 SELECT
@@ -8447,6 +8721,93 @@ func (q *Queries) GetUserReadingHistory(ctx context.Context, arg GetUserReadingH
 	return items, nil
 }
 
+const GetUserReadingSessionsRange = `-- name: GetUserReadingSessionsRange :many
+
+SELECT
+    rh.id, rh.media_item_id, rh.device_id, rh.progress_percentage,
+    rh.reading_session_start, rh.reading_session_end,
+    rh.pages_read, rh.time_spent_seconds, rh.device_metadata, rh.created_at,
+    mi.title, mi.author, mi.library_id, mi.cover_image_path
+FROM reading_history rh
+JOIN media_items mi ON mi.id = rh.media_item_id
+WHERE rh.user_id = $1
+  AND COALESCE(rh.reading_session_end, rh.created_at) >= $2
+  AND COALESCE(rh.reading_session_end, rh.created_at) <= $3
+  AND ($4::uuid[] IS NULL OR mi.library_id = ANY($4::uuid[]))
+ORDER BY rh.created_at ASC
+`
+
+type GetUserReadingSessionsRangeParams struct {
+	UserID            pgtype.UUID        `db:"user_id" json:"user_id"`
+	StartTime         pgtype.Timestamptz `db:"start_time" json:"start_time"`
+	EndTime           pgtype.Timestamptz `db:"end_time" json:"end_time"`
+	VisibleLibraryIds []pgtype.UUID      `db:"visible_library_ids" json:"visible_library_ids"`
+}
+
+type GetUserReadingSessionsRangeRow struct {
+	ID                  pgtype.UUID        `db:"id" json:"id"`
+	MediaItemID         pgtype.UUID        `db:"media_item_id" json:"media_item_id"`
+	DeviceID            pgtype.UUID        `db:"device_id" json:"device_id"`
+	ProgressPercentage  pgtype.Float8      `db:"progress_percentage" json:"progress_percentage"`
+	ReadingSessionStart pgtype.Timestamptz `db:"reading_session_start" json:"reading_session_start"`
+	ReadingSessionEnd   pgtype.Timestamptz `db:"reading_session_end" json:"reading_session_end"`
+	PagesRead           pgtype.Int4        `db:"pages_read" json:"pages_read"`
+	TimeSpentSeconds    pgtype.Int4        `db:"time_spent_seconds" json:"time_spent_seconds"`
+	DeviceMetadata      []byte             `db:"device_metadata" json:"device_metadata"`
+	CreatedAt           pgtype.Timestamptz `db:"created_at" json:"created_at"`
+	Title               string             `db:"title" json:"title"`
+	Author              pgtype.Text        `db:"author" json:"author"`
+	LibraryID           pgtype.UUID        `db:"library_id" json:"library_id"`
+	CoverImagePath      pgtype.Text        `db:"cover_image_path" json:"cover_image_path"`
+}
+
+// STATISTICS (reading sessions) — time spent, pages, streaks, breakdowns.
+// Every stats query scopes to the requesting user's VISIBLE libraries
+// (family lens at the source) and single scan of reading_history.
+// Full session rows for a range (summary math runs in Go: tz buckets,
+// streaks, finished-book detection). The bucket/range key is the session
+// END instant (the push time; NULL falls back to created_at) — the same
+// value the capture stamps every write with.
+func (q *Queries) GetUserReadingSessionsRange(ctx context.Context, arg GetUserReadingSessionsRangeParams) ([]GetUserReadingSessionsRangeRow, error) {
+	rows, err := q.db.Query(ctx, GetUserReadingSessionsRange,
+		arg.UserID,
+		arg.StartTime,
+		arg.EndTime,
+		arg.VisibleLibraryIds,
+	)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+	items := []GetUserReadingSessionsRangeRow{}
+	for rows.Next() {
+		var i GetUserReadingSessionsRangeRow
+		if err := rows.Scan(
+			&i.ID,
+			&i.MediaItemID,
+			&i.DeviceID,
+			&i.ProgressPercentage,
+			&i.ReadingSessionStart,
+			&i.ReadingSessionEnd,
+			&i.PagesRead,
+			&i.TimeSpentSeconds,
+			&i.DeviceMetadata,
+			&i.CreatedAt,
+			&i.Title,
+			&i.Author,
+			&i.LibraryID,
+			&i.CoverImagePath,
+		); err != nil {
+			return nil, err
+		}
+		items = append(items, i)
+	}
+	if err := rows.Err(); err != nil {
+		return nil, err
+	}
+	return items, nil
+}
+
 const GetUserVisibleLibraries = `-- name: GetUserVisibleLibraries :many
 SELECT l.id, l.name, l.description, l.library_type_id, l.created_by_admin_id, l.created_at, l.updated_at, lt.name as type_name, lt.description as type_description,
        COALESCE(lv.is_visible, true) as is_visible

internal/database/queries/queries.sql

@@ -1467,6 +1467,103 @@ SELECT
  ORDER BY read_count DESC
  LIMIT $2;
 
+-- STATISTICS (reading sessions) — time spent, pages, streaks, breakdowns.
+-- Every stats query scopes to the requesting user's VISIBLE libraries
+-- (family lens at the source) and single scan of reading_history.
+
+-- Full session rows for a range (summary math runs in Go: tz buckets,
+-- streaks, finished-book detection). The bucket/range key is the session
+-- END instant (the push time; NULL falls back to created_at) — the same
+-- value the capture stamps every write with.
+-- name: GetUserReadingSessionsRange :many
+SELECT
+    rh.id, rh.media_item_id, rh.device_id, rh.progress_percentage,
+    rh.reading_session_start, rh.reading_session_end,
+    rh.pages_read, rh.time_spent_seconds, rh.device_metadata, rh.created_at,
+    mi.title, mi.author, mi.library_id, mi.cover_image_path
+FROM reading_history rh
+JOIN media_items mi ON mi.id = rh.media_item_id
+WHERE rh.user_id = sqlc.arg('user_id')
+  AND COALESCE(rh.reading_session_end, rh.created_at) >= sqlc.arg('start_time')
+  AND COALESCE(rh.reading_session_end, rh.created_at) <= sqlc.arg('end_time')
+  AND (sqlc.narg('visible_library_ids')::uuid[] IS NULL OR mi.library_id = ANY(sqlc.narg('visible_library_ids')::uuid[]))
+ORDER BY rh.created_at ASC;
+
+-- Per-library aggregation for the same range.
+-- name: GetUserLibraryBreakdown :many
+SELECT
+    l.id::uuid AS library_id,
+    l.name,
+    COUNT(*)::int AS session_count,
+    SUM(COALESCE(rh.time_spent_seconds, 0))::int AS total_seconds,
+    SUM(COALESCE(rh.pages_read, 0))::int AS total_pages,
+    COUNT(DISTINCT rh.media_item_id)::int AS book_count
+FROM reading_history rh
+JOIN media_items mi ON mi.id = rh.media_item_id
+JOIN libraries l ON l.id = mi.library_id
+WHERE rh.user_id = sqlc.arg('user_id')
+  AND COALESCE(rh.reading_session_end, rh.created_at) >= sqlc.arg('start_time')
+  AND COALESCE(rh.reading_session_end, rh.created_at) <= sqlc.arg('end_time')
+  AND (sqlc.narg('visible_library_ids')::uuid[] IS NULL OR mi.library_id = ANY(sqlc.narg('visible_library_ids')::uuid[]))
+GROUP BY l.id, l.name
+ORDER BY total_seconds DESC;
+
+-- Most-read books for a range (minutes), for the top list.
+-- name: GetTopBooksByMinutes :many
+SELECT
+    mi.id::uuid AS media_item_id,
+    mi.title,
+    mi.author,
+    mi.library_id,
+    mi.cover_image_path,
+    SUM(COALESCE(rh.time_spent_seconds, 0))::int AS total_seconds,
+    SUM(COALESCE(rh.pages_read, 0))::int AS total_pages,
+    COUNT(*)::int AS session_count,
+    MAX(rh.created_at) AS last_read
+FROM reading_history rh
+JOIN media_items mi ON mi.id = rh.media_item_id
+WHERE rh.user_id = sqlc.arg('user_id')
+  AND COALESCE(rh.reading_session_end, rh.created_at) >= sqlc.arg('start_time')
+  AND COALESCE(rh.reading_session_end, rh.created_at) <= sqlc.arg('end_time')
+  AND (sqlc.narg('visible_library_ids')::uuid[] IS NULL OR mi.library_id = ANY(sqlc.narg('visible_library_ids')::uuid[]))
+GROUP BY mi.id, mi.title, mi.author, mi.library_id, mi.cover_image_path
+ORDER BY total_seconds DESC
+LIMIT sqlc.arg('limit');
+
+-- Lifetime session rows for ONE book (the book-detail stats card).
+-- name: GetBookReadingSessions :many
+SELECT
+    rh.id, rh.device_id, rh.progress_percentage,
+    rh.reading_session_start, rh.reading_session_end,
+    rh.pages_read, rh.time_spent_seconds, rh.device_metadata, rh.created_at
+FROM reading_history rh
+WHERE rh.user_id = sqlc.arg('user_id')
+  AND rh.media_item_id = sqlc.arg('media_item_id')
+ORDER BY rh.created_at ASC;
+
+-- Distinct ACTIVE days (any captured session) bucketed in the user's
+-- timezone — the streak calendar. Scoped to a long look-back so the
+-- "longest streak" and a current streak longer than the selected range
+-- are both real.
+-- name: GetUserReadingActiveDays :many
+SELECT DISTINCT (COALESCE(rh.reading_session_end, rh.created_at) AT TIME ZONE sqlc.arg('tz')::text)::date::text AS day
+FROM reading_history rh
+JOIN media_items mi ON mi.id = rh.media_item_id
+WHERE rh.user_id = sqlc.arg('user_id')
+  AND COALESCE(rh.reading_session_end, rh.created_at) >= sqlc.arg('start_time')
+  AND (sqlc.narg('visible_library_ids')::uuid[] IS NULL OR mi.library_id = ANY(sqlc.narg('visible_library_ids')::uuid[]))
+ORDER BY day ASC;
+
+-- Device existence probe for capture: the web/app progress paths
+-- historically stuff the user id into DeviceID (it only fed a broadcast
+-- label before stats); a capture row must only reference a REAL device.
+-- name: DeviceExistsForUser :one
+SELECT EXISTS(
+    SELECT 1 FROM devices
+    WHERE id = sqlc.arg('device_id') AND user_id = sqlc.arg('user_id')
+) AS has_device;
+
+
  -- ============================================
 -- DEVICE MANAGEMENT & AUTH
 -- ============================================

internal/handlers/media_detail.go

@@ -16,6 +16,11 @@ type MediaDetail struct {
 	Collections     []database.Collections    `json:"collections"`
 	ReadingProgress *database.ReadingProgress `json:"reading_progress,omitempty"`
 
+	// The viewer's own reading-history card for this book (nil when the
+	// user has no sessions here); rendered as the "Your Reading Stats"
+	// section of the book page.
+	BookStats *BookStatsData `json:"book_stats,omitempty"`
+
 	// Conflict data (if exists)
 	ActiveConflict *ConflictDetailResponse `json:"active_conflict,omitempty"`
 
@@ -27,3 +32,14 @@ type MediaDetail struct {
 	// page's "recently deleted" list with restore/permanent-delete actions.
 	DeletedAnnotations []DeletedAnnotationResponse `json:"deleted_annotations"`
 }
+
+// BookStatsData is the per-book reading-stats card payload.
+type BookStatsData struct {
+	TotalMinutes int
+	TotalPages   int
+	SessionCount int
+	MaxProgress  float64 // 0..1
+	Finished     bool
+	LastSession  string
+	FirstSession string
+}

internal/handlers/stats.go

@@ -0,0 +1,88 @@
+package handlers
+
+import (
+	"bookhoard/internal/database"
+	"bookhoard/internal/services"
+	"net/http"
+
+	"github.com/google/uuid"
+	"github.com/jackc/pgx/v5/pgtype"
+	"github.com/labstack/echo/v5"
+)
+
+// StatsHandler serves the reading-statistics API (/api/stats/*) backed
+// by the StatisticsService. The server owns every conversion: clients
+// receive user-timezone-rendered strings plus raw minute/page counts.
+type StatsHandler struct {
+	statsService *services.StatisticsService
+}
+
+func NewStatsHandler(statsService *services.StatisticsService) *StatsHandler {
+	return &StatsHandler{statsService: statsService}
+}
+
+func mustUser(c *echo.Context) (database.Users, bool) {
+	user, ok := c.Get("user").(database.Users)
+	return user, ok
+}
+
+// Summary handles GET /api/stats/summary?range=7|30|90|year — the /stats
+// page's complete payload: totals, daily arrays, streaks, most-active
+// day, top books, per-library breakdown.
+func (h *StatsHandler) Summary(c *echo.Context) error {
+	user, ok := mustUser(c)
+	if !ok {
+		return echo.NewHTTPError(http.StatusUnauthorized, "invalid user")
+	}
+	summary, err := h.statsService.UserSummary(c.Request().Context(),
+		pgtype.UUID{Bytes: user.ID.Bytes, Valid: true},
+		user.Timezone.String,
+		c.QueryParam("range"),
+	)
+	if err != nil {
+		if err.Error()[:7] == "invalid" {
+			return echo.NewHTTPError(http.StatusBadRequest, err.Error())
+		}
+		return echo.NewHTTPError(http.StatusInternalServerError, err.Error())
+	}
+	return c.JSON(http.StatusOK, summary)
+}
+
+// ThisWeek handles GET /api/stats/this-week — the dashboard widget's
+// data: rolling 7-day totals vs the previous seven days, plus streak.
+func (h *StatsHandler) ThisWeek(c *echo.Context) error {
+	user, ok := mustUser(c)
+	if !ok {
+		return echo.NewHTTPError(http.StatusUnauthorized, "invalid user")
+	}
+	week, err := h.statsService.ThisWeek(c.Request().Context(),
+		pgtype.UUID{Bytes: user.ID.Bytes, Valid: true},
+		user.Timezone.String,
+	)
+	if err != nil {
+		return echo.NewHTTPError(http.StatusInternalServerError, err.Error())
+	}
+	return c.JSON(http.StatusOK, week)
+}
+
+// BookStats handles GET /api/stats/books/:id — the per-book card on the
+// book detail page (lifetime totals + recent sessions).
+func (h *StatsHandler) BookStats(c *echo.Context) error {
+	user, ok := mustUser(c)
+	if !ok {
+		return echo.NewHTTPError(http.StatusUnauthorized, "invalid user")
+	}
+	mediaItemID, err := uuid.Parse(c.Param("id"))
+	if err != nil {
+		return echo.NewHTTPError(http.StatusBadRequest, "invalid media item id")
+	}
+	stats, err := h.statsService.BookStats(c.Request().Context(),
+		pgtype.UUID{Bytes: user.ID.Bytes, Valid: true},
+		mediaItemID,
+		user.Timezone.String,
+	)
+	if err != nil {
+		return echo.NewHTTPError(http.StatusInternalServerError, err.Error())
+	}
+	return c.JSON(http.StatusOK, stats)
+}

internal/router/analytics.go

@@ -8,9 +8,18 @@ func registerAnalyticsRoutes(cfg *Config) {
 
 	protected := e.Group("/api", jwtMiddleware)
 
-	// Analytics routes
+	// Analytics routes (legacy shape; kept for existing API consumers —
+	// the web UI moved to /stats)
 	analytics := protected.Group("/analytics")
 	analytics.GET("/reading-stats", cfg.AnalyticsHandler.GetReadingStats)
 	analytics.GET("/device-usage", cfg.AnalyticsHandler.GetDeviceUsage)
 	analytics.GET("/popular-books", cfg.AnalyticsHandler.GetPopularBooks)
+
+	// Reading-statistics API (/stats page + dashboard widget + per-book
+	// card). Same session seed, service-backed aggregates, user-timezone
+	// bucketing. The legacy /analytics page redirects to /stats.
+	stats := protected.Group("/stats")
+	stats.GET("/summary", cfg.StatsHandler.Summary)
+	stats.GET("/this-week", cfg.StatsHandler.ThisWeek)
+	stats.GET("/books/:id", cfg.StatsHandler.BookStats)
 }

internal/router/frontend.go

@@ -473,8 +473,30 @@ func registerFrontendRoutes(cfg *Config) {
 		sectionData := handlers.MarkActiveConflictsSections(c.Request().Context(), cfg.Queries, userPgID, handlers.BuildSections(visibleSections, libraryID))
 		allSectionsData := handlers.BuildSections(allSections, libraryID)
 
+		// “This week” widget: the user's rolling 7-day reading pulse, from
+		// the same session seed the /stats page uses. Suppressed when the
+		// service fails (dashboard always renders).
+		var week *templates.WeekStatsData
+		if cfg.StatisticsService != nil {
+			weekSvc, weekErr := cfg.StatisticsService.ThisWeek(c.Request().Context(),
+				pgtype.UUID{Bytes: userUUID, Valid: true}, user.Timezone)
+			if weekErr == nil {
+				week = &templates.WeekStatsData{
+					WeekMinutes:   weekSvc.WeekMinutes,
+					WeekPages:     weekSvc.WeekPages,
+					WeekSessions:  weekSvc.WeekSessions,
+					WeekBooks:     weekSvc.WeekBooks,
+					PrevMinutes:   weekSvc.PrevMinutes,
+					ActiveToday:   weekSvc.ActiveToday,
+					CurrentStreak: weekSvc.CurrentStreak,
+				}
+			} else {
+				log.Printf("ThisWeek widget failed: %v", weekErr)
+			}
+		}
+
 		var buf bytes.Buffer
-		err = templates.Dashboard(user, sectionData, allSectionsData, libRes.Libraries, libraryID, prefs.HiddenCollections, limit, errorMsg).Render(c.Request().Context(), &buf)
+		err = templates.Dashboard(user, sectionData, allSectionsData, libRes.Libraries, libraryID, prefs.HiddenCollections, limit, week, errorMsg).Render(c.Request().Context(), &buf)
 		if err != nil {
 			return err
 		}
@@ -948,14 +970,22 @@ func registerFrontendRoutes(cfg *Config) {
 		return c.HTML(http.StatusOK, buf.String())
 	})
 
-	// Analytics page
+	// Analytics page → /stats (the rebuilt reading-statistics page;
+	// nobody bookmarks orphan pages twice).
 	frontendProtected.GET("/analytics", func(c *echo.Context) error {
+		return c.Redirect(http.StatusMovedPermanently, "/stats")
+	})
+
+	// Reading statistics page — per-user by default, with library
+	// breakdown; the per-book tier lives on the book detail page and the
+	// dashboard carries the "this week" widget.
+	frontendProtected.GET("/stats", func(c *echo.Context) error {
 		user, err := getTemplateUserWithTheme(c, cfg)
 		if err != nil {
 			return renderErrorPage(c, "Error loading user", "user_load_error")
 		}
 		var buf bytes.Buffer
-		err = templates.Analytics(user).Render(c.Request().Context(), &buf)
+		err = templates.Stats(user).Render(c.Request().Context(), &buf)
 		if err != nil {
 			return err
 		}
@@ -1577,6 +1607,24 @@ func registerFrontendRoutes(cfg *Config) {
 			UserID:      pgUserID,
 		})
 
+		// Per-book reading stats (the viewer's own history card) — nil
+		// keeps the card off the page for untouched books / other users.
+		var bookStats *handlers.BookStatsData
+		if cfg.StatisticsService != nil {
+			if svcStats, serr := cfg.StatisticsService.BookStats(c.Request().Context(),
+				pgUserID, mediaUUID, user.Timezone); serr == nil && svcStats.SessionCount > 0 {
+				bookStats = &handlers.BookStatsData{
+					TotalMinutes: svcStats.TotalMinutes,
+					TotalPages:   svcStats.TotalPages,
+					SessionCount: svcStats.SessionCount,
+					MaxProgress:  svcStats.MaxProgress,
+					Finished:     svcStats.Finished,
+					FirstSession: svcStats.FirstSession,
+					LastSession:  svcStats.LastSession,
+				}
+			}
+		}
+
 		// Assemble response (no field duplication!)
 		detail := handlers.MediaDetail{
 			MediaItems:         mediaItem, // Embedded - ALL fields available
@@ -1584,6 +1632,7 @@ func registerFrontendRoutes(cfg *Config) {
 			Rating:             rating,
 			Collections:        collections,
 			ReadingProgress:    progress,
+			BookStats:          bookStats,
 			ActiveConflict:     activeConflict,
 			NotesCount:         len(notes),
 			HighlightsCount:    len(highlights),

internal/router/router.go

@@ -52,6 +52,8 @@ type Config struct {
 	WSHandler               *handlers.WSHandler
 	ConflictHandler         *handlers.ConflictHandler
 	AnalyticsHandler        *handlers.AnalyticsHandler
+	StatsHandler            *handlers.StatsHandler
+	StatisticsService       *services.StatisticsService
 	QueueHandler            *handlers.QueueHandler
 	CollectionHandler       *handlers.CollectionHandler
 	Worker                  *services.Worker

internal/services/collection_service.go

@@ -340,9 +340,9 @@ func (s *CollectionService) AddRule(ctx context.Context, collectionID uuid.UUID,
 	}
 
 	updated, err := s.db.UpdateCollectionRulesJSON(ctx, database.UpdateCollectionRulesJSONParams{
-			ID:              pgtype.UUID{Bytes: collectionID, Valid: true},
-			AutoAssignRules: rulesJSON,
-		})
+		ID:              pgtype.UUID{Bytes: collectionID, Valid: true},
+		AutoAssignRules: rulesJSON,
+	})
 	if err != nil {
 		return database.Collections{}, Rule{}, fmt.Errorf("failed to save rules: %w", err)
 	}
@@ -374,9 +374,9 @@ func (s *CollectionService) SetRuleEnabled(ctx context.Context, collectionID uui
 	}
 
 	updated, err := s.db.UpdateCollectionRulesJSON(ctx, database.UpdateCollectionRulesJSONParams{
-			ID:              pgtype.UUID{Bytes: collectionID, Valid: true},
-			AutoAssignRules: rulesJSON,
-		})
+		ID:              pgtype.UUID{Bytes: collectionID, Valid: true},
+		AutoAssignRules: rulesJSON,
+	})
 	if err != nil {
 		return database.Collections{}, fmt.Errorf("failed to save rules: %w", err)
 	}
@@ -410,9 +410,9 @@ func (s *CollectionService) RemoveRule(ctx context.Context, collectionID uuid.UU
 	}
 
 	updated, err := s.db.UpdateCollectionRulesJSON(ctx, database.UpdateCollectionRulesJSONParams{
-			ID:              pgtype.UUID{Bytes: collectionID, Valid: true},
-			AutoAssignRules: rulesJSON,
-		})
+		ID:              pgtype.UUID{Bytes: collectionID, Valid: true},
+		AutoAssignRules: rulesJSON,
+	})
 	if err != nil {
 		return database.Collections{}, fmt.Errorf("failed to save rules: %w", err)
 	}

internal/services/statistics_service.go

@@ -0,0 +1,619 @@
+package services
+
+import (
+	"bookhoard/internal/database"
+	"bookhoard/internal/utils"
+	"context"
+	"encoding/json"
+	"fmt"
+	"log"
+	"time"
+
+	"github.com/google/uuid"
+	"github.com/jackc/pgx/v5/pgtype"
+)
+
+// StatisticsService aggregates reading_history sessions into the
+// reading-stats surfaces: the /stats page, its per-book card, and the
+// dashboard "this week" widget. All day bucketing happens in the
+// REQUESTING user's timezone — every calendar concept here is per-user
+// (server convention; "today" is the user's calendar, never UTC).
+type StatisticsService struct {
+	db *database.Queries
+}
+
+func NewStatisticsService(db *database.Queries) *StatisticsService {
+	return &StatisticsService{db: db}
+}
+
+// finishedThreshold mirrors what the readers push at the end of a book:
+// 0.995 leaves room for a TOC/colophon page pushing just under 100%
+// (percentage is a 0..1 float everywhere on the server).
+const finishedThreshold = 0.995
+
+// streakLookbackDays bounds the streak calendar (both streaks computed
+// over that recent window — "in record").
+const streakLookbackDays = 730
+
+// topBooksLimit is the "most read" list length on the /stats page.
+const topBooksLimit = 5
+
+// StatsRange is an inclusive calendar range in a user's timezone.
+type StatsRange struct {
+	Start time.Time // first instant of the first day
+	End   time.Time // last nanosecond of the last day
+	Days  int
+}
+
+// ResolveStatsRange maps the UI's selector ("7", "30", "90", "year") to
+// an inclusive window ending today in the user's timezone.
+func ResolveStatsRange(tz string, rangeKey string) (StatsRange, error) {
+	loc := utils.UserLocation(tz)
+	now := time.Now().In(loc)
+	// Anchor the end-of-day to the START of today (clock time stripped):
+	// today.AddDate(0,0,1) minus a nanosecond would carry this instant's
+	// clock into tomorrow and resolve "today" a calendar day late.
+	todayStart := time.Date(now.Year(), now.Month(), now.Day(), 0, 0, 0, 0, loc)
+	end := todayStart.AddDate(0, 0, 1).Add(-time.Nanosecond)
+
+	var days int
+	switch rangeKey {
+	case "", "7":
+		days = 7
+	case "30":
+		days = 30
+	case "90":
+		days = 90
+	case "year":
+		// Calendar year to date (Jan 1 → today).
+		jan1 := time.Date(now.Year(), time.January, 1, 0, 0, 0, 0, loc)
+		days = int(now.Sub(jan1).Hours()/24.0) + 1
+		if days < 1 {
+			days = 1
+		}
+	default:
+		return StatsRange{}, fmt.Errorf("invalid range: %s (use 7, 30, 90 or year)", rangeKey)
+	}
+
+	start := todayStart.AddDate(0, 0, -(days - 1))
+	return StatsRange{Start: start, End: end, Days: days}, nil
+}
+
+type DailyStats struct {
+	Date     string `json:"date"` // YYYY-MM-DD, in the user's timezone
+	Minutes  int    `json:"minutes"`
+	Pages    int    `json:"pages"`
+	Sessions int    `json:"sessions"`
+}
+
+type StreakStats struct {
+	// Current counts consecutive active days ending at today; when today
+	// has no session yet, the streak that ends yesterday still counts.
+	Current     int  `json:"current"`
+	Longest     int  `json:"longest"` // longest active streak in record
+	ActiveToday bool `json:"active_today"`
+}
+
+type TopBookStats struct {
+	MediaItemID    string `json:"media_item_id"`
+	Title          string `json:"title"`
+	Author         string `json:"author"`
+	CoverImagePath string `json:"cover_image_path"`
+	Minutes        int    `json:"minutes"`
+	Pages          int    `json:"pages"`
+	Sessions       int    `json:"sessions"`
+	LastRead       string `json:"last_read"`
+}
+
+type LibraryStats struct {
+	LibraryID string `json:"library_id"`
+	Name      string `json:"name"`
+	Minutes   int    `json:"minutes"`
+	Pages     int    `json:"pages"`
+	Sessions  int    `json:"sessions"`
+	Books     int    `json:"books"`
+}
+
+type UserSummaryStats struct {
+	Range             string         `json:"range"`
+	Days              int            `json:"days"`
+	StartDate         string         `json:"start_date"`
+	EndDate           string         `json:"end_date"`
+	TotalMinutes      int            `json:"total_minutes"`
+	TotalPages        int            `json:"total_pages"`
+	SessionCount      int            `json:"session_count"`
+	BooksActive       int            `json:"books_with_activity"`
+	BooksFinished     int            `json:"books_finished"`
+	CompletionRate    float64        `json:"completion_rate"` // finished / books with activity (0 when none)
+	AvgSessionMin     float64        `json:"average_session_minutes"`
+	Daily             []DailyStats   `json:"daily"` // zero-filled across the range
+	Streak            StreakStats    `json:"streak"`
+	MostActiveWeekday string         `json:"most_active_weekday"` // by minutes over the range; "" when nothing
+	MostActiveDay     string         `json:"most_active_day"`     // date with the most minutes
+	MostActiveMinutes int            `json:"most_active_day_minutes"`
+	TopBooks          []TopBookStats `json:"top_books"`
+	LibraryBreakdown  []LibraryStats `json:"library_breakdown"`
+}
+
+type WeekSummaryStats struct {
+	WeekMinutes   int  `json:"week_minutes"`
+	WeekPages     int  `json:"week_pages"`
+	WeekSessions  int  `json:"week_sessions"`
+	WeekBooks     int  `json:"week_books"`
+	PrevMinutes   int  `json:"prev_week_minutes"`
+	PrevPages     int  `json:"prev_week_pages"`
+	PrevSessions  int  `json:"prev_week_sessions"`
+	ActiveToday   bool `json:"active_today"`
+	CurrentStreak int  `json:"current_streak"`
+}
+
+type BookStats struct {
+	MediaItemID    string           `json:"media_item_id"`
+	TotalMinutes   int              `json:"total_minutes"`
+	TotalPages     int              `json:"total_pages"`
+	SessionCount   int              `json:"session_count"`
+	MaxProgress    float64          `json:"max_progress"`
+	Finished       bool             `json:"finished"`
+	FirstSession   string           `json:"first_session"`
+	LastSession    string           `json:"last_session"`
+	RecentSessions []SessionSummary `json:"recent_sessions"` // newest first, capped
+}
+
+type SessionSummary struct {
+	StartedAt string  `json:"started_at"`
+	EndedAt   string  `json:"ended_at"`
+	Minutes   int     `json:"minutes"`
+	Pages     int     `json:"pages"` // 0 when unknown (no page info on the pushes)
+	Progress  float64 `json:"progress"`
+	Source    string  `json:"source"`
+}
+
+// userVisibleLibraryIDs loads the family-lens set for this user (empty →
+// no visible-library filter, i.e. everything is visible by default).
+func (s *StatisticsService) userVisibleLibraryIDs(ctx context.Context, userID pgtype.UUID) ([]pgtype.UUID, error) {
+	rows, err := s.db.GetUserVisibleLibraries(ctx, userID)
+	if err != nil {
+		return nil, fmt.Errorf("failed to check library access: %w", err)
+	}
+	ids := make([]pgtype.UUID, 0, len(rows))
+	for _, lib := range rows {
+		if lib.ID.Valid {
+			ids = append(ids, lib.ID)
+		}
+	}
+	return ids, nil
+}
+
+// visibleOrNil maps an empty visible set to a NULL filter argument.
+func visibleOrNil(ids []pgtype.UUID) []pgtype.UUID {
+	if len(ids) == 0 {
+		return nil
+	}
+	return ids
+}
+
+// UserSummary builds the /stats page payload for a range: totals,
+// zero-filled daily arrays, streaks, most-active day, top books, and
+// the per-library breakdown — one call for the page.
+func (s *StatisticsService) UserSummary(ctx context.Context, userID pgtype.UUID, tz, rangeKey string) (UserSummaryStats, error) {
+	statsRange, err := ResolveStatsRange(tz, rangeKey)
+	if err != nil {
+		return UserSummaryStats{}, err
+	}
+	loc := utils.UserLocation(tz)
+
+	visibleIDs, err := s.userVisibleLibraryIDs(ctx, userID)
+	if err != nil {
+		return UserSummaryStats{}, err
+	}
+
+	sessions, err := s.db.GetUserReadingSessionsRange(ctx, database.GetUserReadingSessionsRangeParams{
+		UserID:            userID,
+		StartTime:         pgtype.Timestamptz{Time: statsRange.Start, Valid: true},
+		EndTime:           pgtype.Timestamptz{Time: statsRange.End, Valid: true},
+		VisibleLibraryIds: visibleOrNil(visibleIDs),
+	})
+	if err != nil {
+		return UserSummaryStats{}, fmt.Errorf("failed to load reading sessions: %w", err)
+	}
+
+	summary := UserSummaryStats{
+		Range:            rangeKey,
+		Days:             statsRange.Days,
+		StartDate:        statsRange.Start.Format("2006-01-02"),
+		EndDate:          statsRange.End.Format("2006-01-02"),
+		Daily:            make([]DailyStats, 0, statsRange.Days),
+		TopBooks:         []TopBookStats{},
+		LibraryBreakdown: []LibraryStats{},
+	}
+
+	// Zero-filled calendar (inclusive of today).
+	dailyMap := make(map[string]*DailyStats, statsRange.Days)
+	for i := 0; i < statsRange.Days; i++ {
+		day := statsRange.Start.AddDate(0, 0, i)
+		entry := DailyStats{Date: day.Format("2006-01-02")}
+		summary.Daily = append(summary.Daily, entry)
+		dailyMap[entry.Date] = &summary.Daily[len(summary.Daily)-1]
+	}
+
+	bookActivity := make(map[string]bool, len(sessions))
+	finishedSet := make(map[string]bool)
+	var totalSessionSeconds int64
+	weekdayMinutes := make(map[time.Weekday]int)
+
+	for _, sess := range sessions {
+		// The bucket key matches the SQL range filter: the session END
+		// instant (what the capture stamps; NULL falls back to
+		// created_at) — not the row's created_at.
+		ts := sess.CreatedAt
+		if sess.ReadingSessionEnd.Valid {
+			ts = sess.ReadingSessionEnd
+		}
+		key := dayKey(ts, loc)
+		entry, ok := dailyMap[key]
+		if !ok {
+			continue // defensive: outside the inclusive window
+		}
+
+		if sess.TimeSpentSeconds.Valid {
+			seconds := int64(sess.TimeSpentSeconds.Int32)
+			totalSessionSeconds += seconds
+			summary.TotalMinutes += int(seconds / 60)
+			entry.Minutes += int(seconds / 60)
+		}
+		if sess.PagesRead.Valid {
+			summary.TotalPages += int(sess.PagesRead.Int32)
+			entry.Pages += int(sess.PagesRead.Int32)
+		}
+		entry.Sessions++
+		summary.SessionCount++
+
+		mediaUUID, err := uuid.FromBytes(sess.MediaItemID.Bytes[0:16])
+		if err == nil {
+			key := mediaUUID.String()
+			bookActivity[key] = true
+			if sess.ProgressPercentage.Valid && sess.ProgressPercentage.Float64 >= finishedThreshold {
+				finishedSet[key] = true
+			}
+		}
+
+		localTime := ts.Time.In(loc)
+		if sess.TimeSpentSeconds.Valid {
+			weekdayMinutes[localTime.Weekday()] += int(sess.TimeSpentSeconds.Int32) / 60
+		}
+	}
+
+	summary.BooksActive = len(bookActivity)
+	summary.BooksFinished = len(finishedSet)
+	if summary.BooksActive > 0 {
+		summary.CompletionRate = float64(summary.BooksFinished) / float64(summary.BooksActive)
+	}
+	if summary.SessionCount > 0 {
+		summary.AvgSessionMin = float64(totalSessionSeconds) / float64(summary.SessionCount) / 60.0
+	}
+
+	// Most-active weekday by minutes (empty string before any signal).
+	dayNames := []string{"Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"}
+	bestWeekdayMinutes := -1
+	var bestWeekday time.Weekday
+	for wd, mins := range weekdayMinutes {
+		if mins > bestWeekdayMinutes {
+			bestWeekdayMinutes = mins
+			bestWeekday = wd
+		}
+	}
+	if bestWeekdayMinutes > 0 {
+		summary.MostActiveWeekday = dayNames[bestWeekday]
+	}
+
+	for _, d := range summary.Daily {
+		if d.Minutes > summary.MostActiveMinutes {
+			summary.MostActiveMinutes = d.Minutes
+			summary.MostActiveDay = d.Date
+		}
+	}
+
+	// Streaks: a dedicated lightweight calendar (~2y look-back) so a
+	// current streak longer than the selected range is still real.
+	activeDays, err := s.db.GetUserReadingActiveDays(ctx, database.GetUserReadingActiveDaysParams{
+		Tz:                loc.String(),
+		UserID:            userID,
+		StartTime:         pgtype.Timestamptz{Time: statsRange.Start.AddDate(0, 0, -(streakLookbackDays - statsRange.Days)), Valid: true},
+		VisibleLibraryIds: visibleOrNil(visibleIDs),
+	})
+	if err == nil {
+		summary.Streak = computeStreaks(activeDays, statsRange.End.Format("2006-01-02"))
+	} else {
+		log.Printf("stats: active-days query failed: %v", err)
+	}
+
+	// Top books by minutes in the range.
+	topRows, err := s.db.GetTopBooksByMinutes(ctx, database.GetTopBooksByMinutesParams{
+		UserID:            userID,
+		StartTime:         pgtype.Timestamptz{Time: statsRange.Start, Valid: true},
+		EndTime:           pgtype.Timestamptz{Time: statsRange.End, Valid: true},
+		VisibleLibraryIds: visibleOrNil(visibleIDs),
+		Limit:             topBooksLimit,
+	})
+	if err == nil {
+		for _, row := range topRows {
+			entry := TopBookStats{
+				Title:          row.Title,
+				Author:         row.Author.String,
+				CoverImagePath: utils.ResolveMediaURL(row.LibraryID, row.CoverImagePath),
+				Minutes:        int(row.TotalSeconds) / 60,
+				Pages:          int(row.TotalPages),
+				Sessions:       int(row.SessionCount),
+			}
+			if row.MediaItemID.Valid {
+				entry.MediaItemID = uuid.UUID(row.MediaItemID.Bytes).String()
+			}
+			if row.LastRead != nil {
+				if t, ok := row.LastRead.(time.Time); ok {
+					entry.LastRead = utils.FormatTimeInTimezone(t, tz)
+				}
+			}
+			summary.TopBooks = append(summary.TopBooks, entry)
+		}
+	}
+
+	// Per-library breakdown in the range.
+	libRows, err := s.db.GetUserLibraryBreakdown(ctx, database.GetUserLibraryBreakdownParams{
+		UserID:            userID,
+		StartTime:         pgtype.Timestamptz{Time: statsRange.Start, Valid: true},
+		EndTime:           pgtype.Timestamptz{Time: statsRange.End, Valid: true},
+		VisibleLibraryIds: visibleOrNil(visibleIDs),
+	})
+	if err == nil {
+		for _, row := range libRows {
+			entry := LibraryStats{
+				Name:     row.Name,
+				Minutes:  int(row.TotalSeconds) / 60,
+				Pages:    int(row.TotalPages),
+				Sessions: int(row.SessionCount),
+				Books:    int(row.BookCount),
+			}
+			if row.LibraryID.Valid {
+				entry.LibraryID = uuid.UUID(row.LibraryID.Bytes).String()
+			}
+			summary.LibraryBreakdown = append(summary.LibraryBreakdown, entry)
+		}
+	}
+
+	return summary, nil
+}
+
+// ThisWeek builds the dashboard widget: the current rolling 7-day
+// window (today inclusive) versus the previous seven days, plus the
+// streak context. One scan over 14 days, split in Go.
+func (s *StatisticsService) ThisWeek(ctx context.Context, userID pgtype.UUID, tz string) (WeekSummaryStats, error) {
+	statsRange, err := ResolveStatsRange(tz, "7")
+	if err != nil {
+		return WeekSummaryStats{}, err
+	}
+	loc := utils.UserLocation(tz)
+
+	visibleIDs, err := s.userVisibleLibraryIDs(ctx, userID)
+	if err != nil {
+		return WeekSummaryStats{}, err
+	}
+
+	// Scan the 14-day window: [start - 7 days, end].
+	scanStart := statsRange.Start.AddDate(0, 0, -7)
+	sessions, err := s.db.GetUserReadingSessionsRange(ctx, database.GetUserReadingSessionsRangeParams{
+		UserID:            userID,
+		StartTime:         pgtype.Timestamptz{Time: scanStart, Valid: true},
+		EndTime:           pgtype.Timestamptz{Time: statsRange.End, Valid: true},
+		VisibleLibraryIds: visibleOrNil(visibleIDs),
+	})
+	if err != nil {
+		return WeekSummaryStats{}, fmt.Errorf("failed to load reading sessions: %w", err)
+	}
+
+	week := map[string]bool{statsRange.Start.Format("2006-01-02"): true}
+	for i := 0; i < statsRange.Days; i++ {
+		week[statsRange.Start.AddDate(0, 0, i).Format("2006-01-02")] = true
+	}
+
+	out := WeekSummaryStats{
+		ActiveToday:   week[statsRange.End.Format("2006-01-02")],
+		CurrentStreak: 0,
+	}
+	booksThis, booksPrev := make(map[string]bool), make(map[string]bool)
+
+	for _, sess := range sessions {
+		// Same bucket key as UserSummary: the session END instant.
+		ts := sess.CreatedAt
+		if sess.ReadingSessionEnd.Valid {
+			ts = sess.ReadingSessionEnd
+		}
+		key := dayKey(ts, loc)
+		minutes := 0
+		if sess.TimeSpentSeconds.Valid {
+			minutes = int(sess.TimeSpentSeconds.Int32) / 60
+		}
+		pages := 0
+		if sess.PagesRead.Valid {
+			pages = int(sess.PagesRead.Int32)
+		}
+		mediaUUID, err := uuid.FromBytes(sess.MediaItemID.Bytes[0:16])
+		var bookKey string
+		if err == nil {
+			bookKey = mediaUUID.String()
+		}
+
+		if week[key] { // current 7 days
+			out.WeekMinutes += minutes
+			out.WeekPages += pages
+			out.WeekSessions++
+			if bookKey != "" {
+				booksThis[bookKey] = true
+			}
+		} else { // previous 7 days
+			out.PrevMinutes += minutes
+			out.PrevPages += pages
+			out.PrevSessions++
+			if bookKey != "" {
+				booksPrev[bookKey] = true
+			}
+		}
+	}
+	out.WeekBooks = len(booksThis)
+	_ = booksPrev
+
+	activeDays, err := s.db.GetUserReadingActiveDays(ctx, database.GetUserReadingActiveDaysParams{
+		Tz:                loc.String(),
+		UserID:            userID,
+		StartTime:         pgtype.Timestamptz{Time: statsRange.Start.AddDate(0, 0, -(streakLookbackDays - statsRange.Days)), Valid: true},
+		VisibleLibraryIds: visibleOrNil(visibleIDs),
+	})
+	if err == nil {
+		out.CurrentStreak = computeStreaks(activeDays, statsRange.End.Format("2006-01-02")).Current
+		out.ActiveToday = computeStreaks(activeDays, statsRange.End.Format("2006-01-02")).ActiveToday
+	}
+
+	return out, nil
+}
+
+// BookStats is the per-book card: lifetime totals + the most recent
+// sessions (bounded so the detail page never scans unbounded history).
+func (s *StatisticsService) BookStats(ctx context.Context, userID pgtype.UUID, mediaItemID uuid.UUID, tz string) (BookStats, error) {
+	sessions, err := s.db.GetBookReadingSessions(ctx, database.GetBookReadingSessionsParams{
+		UserID:      userID,
+		MediaItemID: pgtype.UUID{Bytes: mediaItemID, Valid: true},
+	})
+	if err != nil {
+		return BookStats{}, fmt.Errorf("failed to load book sessions: %w", err)
+	}
+
+	out := BookStats{
+		MediaItemID:    mediaItemID.String(),
+		RecentSessions: []SessionSummary{},
+	}
+	for i, sess := range sessions {
+		if sess.TimeSpentSeconds.Valid {
+			out.TotalMinutes += int(sess.TimeSpentSeconds.Int32) / 60
+		}
+		if sess.PagesRead.Valid {
+			out.TotalPages += int(sess.PagesRead.Int32)
+		}
+		out.SessionCount++
+		if sess.ProgressPercentage.Valid && sess.ProgressPercentage.Float64 > out.MaxProgress {
+			out.MaxProgress = sess.ProgressPercentage.Float64
+		}
+		out.Finished = out.Finished || (sess.ProgressPercentage.Valid && sess.ProgressPercentage.Float64 >= finishedThreshold)
+
+		start := ""
+		if sess.ReadingSessionStart.Valid {
+			start = utils.FormatTimeInTimezone(sess.ReadingSessionStart.Time, tz)
+		}
+		end := ""
+		if sess.ReadingSessionEnd.Valid {
+			end = utils.FormatTimeInTimezone(sess.ReadingSessionEnd.Time, tz)
+		}
+		if sess.ReadingSessionEnd.Valid {
+			if i == 0 {
+				out.FirstSession = end
+			}
+			out.LastSession = end // ascending order → last assignment wins
+		}
+
+		if i >= len(sessions)-10 { // the most recent 10 sessions only
+			summary := SessionSummary{
+				StartedAt: start,
+				EndedAt:   end,
+				Minutes:   int(sess.TimeSpentSeconds.Int32) / 60,
+				Source:    metadataSource(sess.DeviceMetadata),
+			}
+			if sess.PagesRead.Valid {
+				summary.Pages = int(sess.PagesRead.Int32)
+			}
+			if sess.ProgressPercentage.Valid {
+				summary.Progress = sess.ProgressPercentage.Float64
+			}
+			out.RecentSessions = append(out.RecentSessions, summary)
+		}
+	}
+	// Most-recent first for display.
+	for i, j := 0, len(out.RecentSessions)-1; i < j; i, j = i+1, j-1 {
+		out.RecentSessions[i], out.RecentSessions[j] = out.RecentSessions[j], out.RecentSessions[i]
+	}
+
+	return out, nil
+}
+
+// computeStreaks walks an ascending ISO-date list (the active-day
+// calendar in the user's timezone) anchored at TODAY's date.
+func computeStreaks(activeDays []string, today string) StreakStats {
+	activeSet := make(map[string]bool, len(activeDays))
+	for _, d := range activeDays {
+		activeSet[d] = true
+	}
+
+	out := StreakStats{ActiveToday: activeSet[today], Current: 0, Longest: 0}
+
+	// Current: walk back from today; an inactive TODAY falls through to
+	// yesterday so a not-yet-read day doesn't erase a live streak.
+	anchor := today
+	if !activeSet[anchor] {
+		if d, err := time.Parse("2006-01-02", today); err == nil {
+			anchor = d.AddDate(0, 0, -1).Format("2006-01-02")
+		}
+	}
+	for cur := anchor; activeSet[cur]; {
+		out.Current++
+		d, err := time.Parse("2006-01-02", cur)
+		if err != nil {
+			break
+		}
+		cur = d.AddDate(0, 0, -1).Format("2006-01-02")
+	}
+
+	// Longest run in the ascending ordered list.
+	run := 0
+	var prev string
+	for _, d := range activeDays {
+		if prev != "" && nextDay(prev) == d {
+			run++
+		} else {
+			run = 1
+		}
+		if run > out.Longest {
+			out.Longest = run
+		}
+		prev = d
+	}
+
+	return out
+}
+
+// nextDay returns the day after an ISO date, preserving the format.
+func nextDay(iso string) string {
+	d, err := time.Parse("2006-01-02", iso)
+	if err != nil {
+		return ""
+	}
+	return d.AddDate(0, 0, 1).Format("2006-01-02")
+}
+
+// dayKey buckets a session instant into the user's calendar date.
+func dayKey(ts pgtype.Timestamptz, loc *time.Location) string {
+	if !ts.Valid {
+		return ""
+	}
+	return ts.Time.In(loc).Format("2006-01-02")
+}
+
+// metadataSource extracts the capture's source tag from device_metadata.
+func metadataSource(raw []byte) string {
+	if len(raw) == 0 {
+		return ""
+	}
+	var meta struct {
+		Source string `json:"source"`
+	}
+	if jsonErr := json.Unmarshal(raw, &meta); jsonErr == nil {
+		return meta.Source
+	}
+	return ""
+}

internal/sync/progress.go

@@ -597,9 +597,96 @@ func (s *ProgressService) SaveProgress(ctx context.Context, req SaveProgressRequ
 		)
 	}
 
+	// Reading-history capture: threading stats off the sync stream. Every
+	// successful progress write yields one reading_history session row —
+	// the span since the PREVIOUS write instant (bounds are one or the
+	// other: the row is recorded regardless, time attribution is
+	// conservative). Client cadence drives the granularity (web/app
+	// debounced pushes, KOReader page-count pushes); nothing second-level
+	// is promised and nothing client-side changes.
+	s.captureReadingSession(ctx, req, existing, hasExisting, result)
+
 	return result, nil
 }
 
+// maxAttributedSessionSeconds caps a derived session: pushes farther
+// apart than this carry unattributable idle time (overnight suspend →
+// resume, offline queue flushes) and are kept as zero-second markers
+// instead of inflating totals.
+const maxAttributedSessionSeconds = int32(2 * 60 * 60)
+
+// captureReadingSession records one reading_history row for this push.
+// Never fails the sync: capture errors are logged and swallowed.
+func (s *ProgressService) captureReadingSession(ctx context.Context, req SaveProgressRequest, existing database.ReadingProgress, hasExisting bool, saved database.ReadingProgress) {
+	var seconds int32
+	sessionEnd := saved.LastReadAt
+	sessionStart := sessionEnd // first-contact writes start at the push itself
+	if sessionEnd.Valid && hasExisting && existing.LastReadAt.Valid {
+		sessionStart = existing.LastReadAt
+		if elapsed := int32(sessionEnd.Time.Sub(existing.LastReadAt.Time).Seconds()); elapsed > 0 {
+			if elapsed <= maxAttributedSessionSeconds {
+				seconds = elapsed // verified-continuous span
+			} // else: idle gap — marker row, zero time
+		}
+	}
+
+	// Pages read: only when both sides carry a real page index (0 means
+	// unknown for several clients, e.g. LOC-less KOReader pushes).
+	var pages pgtype.Int4
+	if hasExisting && existing.CurrentPage.Valid && existing.CurrentPage.Int32 > 0 &&
+		saved.CurrentPage.Valid && saved.CurrentPage.Int32 > 0 {
+		if deltaPages := saved.CurrentPage.Int32 - existing.CurrentPage.Int32; deltaPages > 0 && deltaPages <= 5000 {
+			pages = pgtype.Int4{Int32: deltaPages, Valid: true}
+		}
+	}
+
+	// device_id references real devices (FK). The web/app progress paths
+	// historically stuff the USER id into DeviceID (it only fed a
+	// broadcast label before stats existed) — probe before writing,
+	// otherwise capture a device-less session and keep the label in
+	// metadata only.
+	var deviceID pgtype.UUID
+	if req.DeviceID.Valid {
+		exists, probeErr := s.db.DeviceExistsForUser(ctx, database.DeviceExistsForUserParams{
+			DeviceID: req.DeviceID,
+			UserID:   req.UserID,
+		})
+		if probeErr == nil && exists {
+			deviceID = req.DeviceID
+		}
+	}
+	metadata := map[string]string{"source": req.Source}
+
+	_, err := s.db.CreateReadingHistory(ctx, database.CreateReadingHistoryParams{
+		UserID:              req.UserID,
+		MediaItemID:         req.MediaItemID,
+		DeviceID:            deviceID,
+		ProgressPercentage:  saved.Percentage,
+		ReadingSessionStart: sessionStart,
+		ReadingSessionEnd:   sessionEnd,
+		PagesRead:           pages,
+		TimeSpentSeconds:    pgtype.Int4{Int32: seconds, Valid: true},
+		DeviceMetadata:      mustJSON(metadata),
+	})
+	if err != nil {
+		log.Printf("reading-history capture failed (non-fatal) for %s: %v", uniqueKeyString(req), err)
+	}
+}
+
+func uniqueKeyString(req SaveProgressRequest) string {
+	return uuid.UUID(req.MediaItemID.Bytes).String()
+}
+
+// mustJSON marshals metadata or an empty document on failure — capture
+// must never break on a serialization corner.
+func mustJSON(v interface{}) []byte {
+	data, err := json.Marshal(v)
+	if err != nil {
+		return []byte(`{}`)
+	}
+	return data
+}
+
 func buildProgressSnapshot(req SaveProgressRequest) map[string]interface{} {
 	data := map[string]interface{}{}
 	if req.Percentage != nil {