refactor(progress): ProgressService required at construction; delete the 9 unreachable erase-fallbacks

Batch H1 step 3a. The ceiling census (exhaustive UpdateUniversalProgress
grep) found 9 nil-guarded `if progressSvc != nil { funnel } else { raw
erase-write }` fallbacks — the survey's "four" under-counted kobo.go,
which has FOUR sites (Markup ReadingSync, Markup last-read-place,
AnalyticsGettests, SyncFromServer), plus one each in media.go, queue.go
and koreader.go. All unreachable: the service is created unconditionally
at main.go:127 and wired into every handler and the queue processor; the
test harness wires them too.

The erasure pattern is now unrepresentable:
- NewMediaHandler / NewKOReaderHandler / NewKoboHandler / both
  NewSyncQueueProcessor flavors take the ProgressService as a REQUIRED
  constructor arg; the SetProgressService setters are gone.
- Every fallback body (raw UpdateUniversalProgress with explicit-NULL
  pgtypes for viewport/scroll/panel/reading_mode/zoom and no
  audio_offset_seconds/context_text) is deleted; each write funnels
  through SaveProgress with the LWW seed, so fields the writer doesn't
  know survive.
- Removed the now-dead koreader pg-type helpers (textPtrToPgText,
  intPtrToPgInt4, int64PtrToPgInt8) and their self-tests.

Behavior deltas (stored-row content, no wire shape changes —
KOReader/Kobo response pins stayed green):
- KOReader fallback used to write explicit NULL viewports and drop the
  context_text the koplugin sends; the funneled mainline already maps
  book.ContextText.
- Queue flushes no longer overwrite chapter_progress with the book
  percentage (bogus data; preserved via the seed).
- A web PUT without percentage no longer writes 0% via the deleted
  fallback; percentage seeds from the stored row.

Contract suite: KOReader×4 + Kobo×3 pins green.

internal/handlers/media.go

@@ -180,11 +180,15 @@ type MediaHandler struct {
 	annotationSvc  *wsync.AnnotationService
 }
 
-func NewMediaHandler(db *database.Queries, libraryService *services.LibraryService, worker ...*services.Worker) *MediaHandler {
+// NewMediaHandler requires the shared ProgressService — progress writes
+// must funnel through SaveProgress (the LWW-seeded canonical writer);
+// a nil service has nowhere to fall back to and must not be wired.
+func NewMediaHandler(db *database.Queries, libraryService *services.LibraryService, progressSvc *wsync.ProgressService, worker ...*services.Worker) *MediaHandler {
 	mh := &MediaHandler{
 		db:             db,
 		libraryService: libraryService,
 		searchService:  services.NewSearchService(db),
+		progressSvc:    progressSvc,
 	}
 	if len(worker) > 0 && worker[0] != nil {
 		mh.worker = worker[0]
@@ -192,10 +196,6 @@ func NewMediaHandler(db *database.Queries, libraryService *services.LibraryServi
 	return mh
 }
 
-func (mh *MediaHandler) SetProgressService(svc *wsync.ProgressService) {
-	mh.progressSvc = svc
-}
-
 func (mh *MediaHandler) SetAnnotationService(svc *wsync.AnnotationService) {
 	mh.annotationSvc = svc
 }
@@ -1281,66 +1281,21 @@ func (mh *MediaHandler) UpdateMediaReadingProgress(c *echo.Context) error {
 	req.DeviceName = deviceLabel
 	req.Broadcast = true
 
-	if mh.progressSvc != nil {
-		if req.Percentage != nil && *req.Percentage < 0.005 {
-			existing, err := mh.db.GetUniversalProgress(c.Request().Context(), database.GetUniversalProgressParams{
-				MediaItemID: pgtype.UUID{Bytes: mediaUUID, Valid: true},
-				UserID:      pgtype.UUID{Bytes: userUUID, Valid: true},
-			})
-			if err == nil && existing.Percentage.Valid && existing.Percentage.Float64 > 0.01 {
-				return c.JSON(http.StatusOK, map[string]string{"status": "ignored"})
-			}
+	if req.Percentage != nil && *req.Percentage < 0.005 {
+		existing, err := mh.db.GetUniversalProgress(c.Request().Context(), database.GetUniversalProgressParams{
+			MediaItemID: pgtype.UUID{Bytes: mediaUUID, Valid: true},
+			UserID:      pgtype.UUID{Bytes: userUUID, Valid: true},
+		})
+		if err == nil && existing.Percentage.Valid && existing.Percentage.Float64 > 0.01 {
+			return c.JSON(http.StatusOK, map[string]string{"status": "ignored"})
 		}
-
-		result, err := mh.progressSvc.SaveProgress(c.Request().Context(), req)
-		if err != nil {
-			return c.JSON(http.StatusInternalServerError, map[string]string{"error": err.Error()})
-		}
-		return c.JSON(http.StatusOK, result)
 	}
 
-	percentage := 0.0
-	if req.Percentage != nil {
-		percentage = *req.Percentage
-	}
-	epubcfi := ""
-	if req.Epubcfi != nil {
-		epubcfi = *req.Epubcfi
-	}
-	currentPage := int32(0)
-	if req.CurrentPage != nil {
-		currentPage = int32(*req.CurrentPage)
-	}
-	totalPages := int32(0)
-	if req.TotalPages != nil {
-		totalPages = int32(*req.TotalPages)
-	}
-
-	progress, err := mh.db.UpdateUniversalProgress(c.Request().Context(), database.UpdateUniversalProgressParams{
-		MediaItemID:     pgtype.UUID{Bytes: mediaUUID, Valid: true},
-		UserID:          pgtype.UUID{Bytes: userUUID, Valid: true},
-		Percentage:      pgtype.Float8{Float64: percentage, Valid: true},
-		CharacterOffset: pgtype.Int8{Valid: false},
-		Epubcfi:         pgtype.Text{String: epubcfi, Valid: epubcfi != ""},
-		Chapter:         pgtype.Int4{Valid: false},
-		ChapterProgress: pgtype.Float8{Valid: false},
-		ViewportX:       pgtype.Float8{Valid: false},
-		ViewportY:       pgtype.Float8{Valid: false},
-		ZoomLevel:       pgtype.Float8{Valid: false},
-		ScrollPositionX: pgtype.Float8{Valid: false},
-		ScrollPositionY: pgtype.Float8{Valid: false},
-		PanelNumber:     pgtype.Int4{Valid: false},
-		ReadingMode:     pgtype.Text{Valid: false},
-		LastSyncDevice:  pgtype.Text{String: "web", Valid: true},
-		LastSyncSource:  pgtype.Text{String: "web", Valid: true},
-		CurrentPage:     pgtype.Int4{Int32: currentPage, Valid: true},
-		TotalPages:      pgtype.Int4{Int32: totalPages, Valid: totalPages > 0},
-	})
+	result, err := mh.progressSvc.SaveProgress(c.Request().Context(), req)
 	if err != nil {
 		return c.JSON(http.StatusInternalServerError, map[string]string{"error": err.Error()})
 	}
-
-	return c.JSON(http.StatusOK, progress)
+	return c.JSON(http.StatusOK, result)
 }
 
 // DeleteMediaReadingProgress handles DELETE /api/media-items/:id/progress