feat(users): audio_resume_rewind_seconds column

Per-user resume rewind for the audiobook/podcast player: how many
seconds (0/5/10) before the saved position playback starts, both on
open-resume and again on every genuine unpause. Motivated by the car
startup case — exact resume loses the listener's place, and the
PlaybackRequestResolver path (phone UI, Android Auto, media buttons)
all funnel through one start position.

0 = exact resume (default), so the column is inert until the profile
page sets it. Follows the default_audio_speed / keep_screen_awake
precedent: idempotent ALTER in schema.sql (re-runs on every boot),
explicit GetUser SELECT, dedicated :exec update. Handler-side strict
allow-list {0,5,10} lands with the API slice.

database/schema/schema.sql

@@ -48,6 +48,14 @@ ALTER TABLE users ADD COLUMN IF NOT EXISTS default_audio_speed REAL NOT NULL DEF
 -- mid-session. On by default; the profile page's On/Off dropdown owns it.
 ALTER TABLE users ADD COLUMN IF NOT EXISTS keep_screen_awake BOOLEAN NOT NULL DEFAULT TRUE;
 
+-- Audio resume rewind: seconds before the saved position the
+-- audiobook/podcast player starts (on open-resume AND again on every
+-- genuine unpause — the re-orientation gap, never stacked). Strict
+-- allow-list 0/5/10 enforced handler-side; 0 = exact resume. The
+-- profile page's dropdown owns it; the chapters payload carries it to
+-- every client (web + Android, incl. the car path).
+ALTER TABLE users ADD COLUMN IF NOT EXISTS audio_resume_rewind_seconds INT NOT NULL DEFAULT 0;
+
 -- Create system_settings table
 CREATE TABLE IF NOT EXISTS system_settings (
     id UUID PRIMARY KEY DEFAULT gen_random_uuid(),

internal/database/models.go

@@ -654,4 +654,5 @@ type Users struct {
 	UpdatedAt                pgtype.Timestamptz `db:"updated_at" json:"updated_at"`
 	DefaultAudioSpeed        float32            `db:"default_audio_speed" json:"default_audio_speed"`
 	KeepScreenAwake          bool               `db:"keep_screen_awake" json:"keep_screen_awake"`
+	AudioResumeRewindSeconds int32              `db:"audio_resume_rewind_seconds" json:"audio_resume_rewind_seconds"`
 }

internal/database/querier.go

@@ -894,6 +894,7 @@ type Querier interface {
 	UpdateSystemSetting(ctx context.Context, arg UpdateSystemSettingParams) error
 	// Update universal progress
 	UpdateUniversalProgress(ctx context.Context, arg UpdateUniversalProgressParams) (ReadingProgress, error)
+	UpdateUserAudioResumeRewind(ctx context.Context, arg UpdateUserAudioResumeRewindParams) error
 	UpdateUserDefaultAudioSpeed(ctx context.Context, arg UpdateUserDefaultAudioSpeedParams) error
 	UpdateUserKeepScreenAwake(ctx context.Context, arg UpdateUserKeepScreenAwakeParams) error
 	UpdateUserMaxDevices(ctx context.Context, arg UpdateUserMaxDevicesParams) (Users, error)

internal/database/queries.sql.go

@@ -11407,6 +11407,7 @@ SELECT
     u.timezone,
     u.default_audio_speed,
     u.keep_screen_awake,
+    u.audio_resume_rewind_seconds,
     (SELECT COUNT(*) FROM devices WHERE user_id = u.id) as device_count
 FROM users u
 WHERE u.id = $1
@@ -11426,6 +11427,7 @@ type GetUserRow struct {
 	Timezone                 pgtype.Text        `db:"timezone" json:"timezone"`
 	DefaultAudioSpeed        float32            `db:"default_audio_speed" json:"default_audio_speed"`
 	KeepScreenAwake          bool               `db:"keep_screen_awake" json:"keep_screen_awake"`
+	AudioResumeRewindSeconds int32              `db:"audio_resume_rewind_seconds" json:"audio_resume_rewind_seconds"`
 	DeviceCount              int64              `db:"device_count" json:"device_count"`
 }
 
@@ -11446,6 +11448,7 @@ func (q *Queries) GetUser(ctx context.Context, id pgtype.UUID) (GetUserRow, erro
 		&i.Timezone,
 		&i.DefaultAudioSpeed,
 		&i.KeepScreenAwake,
+		&i.AudioResumeRewindSeconds,
 		&i.DeviceCount,
 	)
 	return i, err
@@ -20287,6 +20290,20 @@ func (q *Queries) UpdateUniversalProgress(ctx context.Context, arg UpdateUnivers
 	return i, err
 }
 
+const UpdateUserAudioResumeRewind = `-- name: UpdateUserAudioResumeRewind :exec
+UPDATE users SET audio_resume_rewind_seconds = $2, updated_at = NOW() WHERE id = $1
+`
+
+type UpdateUserAudioResumeRewindParams struct {
+	ID                       pgtype.UUID `db:"id" json:"id"`
+	AudioResumeRewindSeconds int32       `db:"audio_resume_rewind_seconds" json:"audio_resume_rewind_seconds"`
+}
+
+func (q *Queries) UpdateUserAudioResumeRewind(ctx context.Context, arg UpdateUserAudioResumeRewindParams) error {
+	_, err := q.db.Exec(ctx, UpdateUserAudioResumeRewind, arg.ID, arg.AudioResumeRewindSeconds)
+	return err
+}
+
 const UpdateUserDefaultAudioSpeed = `-- name: UpdateUserDefaultAudioSpeed :exec
 UPDATE users SET default_audio_speed = $2, updated_at = NOW() WHERE id = $1
 `
@@ -20317,7 +20334,7 @@ func (q *Queries) UpdateUserKeepScreenAwake(ctx context.Context, arg UpdateUserK
 
 const UpdateUserMaxDevices = `-- name: UpdateUserMaxDevices :one
 UPDATE users SET max_devices = $2, updated_at = NOW() WHERE id = $1
-RETURNING id, email, username, password_hash, first_name, last_name, role, theme, max_devices, created_at, timezone, updated_at, default_audio_speed, keep_screen_awake
+RETURNING id, email, username, password_hash, first_name, last_name, role, theme, max_devices, created_at, timezone, updated_at, default_audio_speed, keep_screen_awake, audio_resume_rewind_seconds
 `
 
 type UpdateUserMaxDevicesParams struct {
@@ -20343,6 +20360,7 @@ func (q *Queries) UpdateUserMaxDevices(ctx context.Context, arg UpdateUserMaxDev
 		&i.UpdatedAt,
 		&i.DefaultAudioSpeed,
 		&i.KeepScreenAwake,
+		&i.AudioResumeRewindSeconds,
 	)
 	return i, err
 }

internal/database/queries/queries.sql

@@ -30,6 +30,7 @@ SELECT
     u.timezone,
     u.default_audio_speed,
     u.keep_screen_awake,
+    u.audio_resume_rewind_seconds,
     (SELECT COUNT(*) FROM devices WHERE user_id = u.id) as device_count
 FROM users u
 WHERE u.id = $1;
@@ -526,6 +527,9 @@ UPDATE users SET default_audio_speed = $2, updated_at = NOW() WHERE id = $1;
 -- name: UpdateUserKeepScreenAwake :exec
 UPDATE users SET keep_screen_awake = $2, updated_at = NOW() WHERE id = $1;
 
+-- name: UpdateUserAudioResumeRewind :exec
+UPDATE users SET audio_resume_rewind_seconds = $2, updated_at = NOW() WHERE id = $1;
+
 -- Per-book playback speed preference (player plan §8).
 
 -- name: GetAudioPlaybackSpeed :one