feat(backend): remove browse-page cache, add Sentry/GlitchTip, rename MinIO buckets

- Remove BrowseStore interface + all browse MinIO ops (PutBrowsePage, GetBrowsePage,
  BrowseObjectKey, putBrowse, getBrowse); the /api/browse endpoint was replaced by
  the Meilisearch-backed /api/catalogue route
- Remove browse_refresh.go and the 6h browse refresh ticker in runner
- Add Sentry/GlitchTip error tracking to both backend and runner binaries via
  github.com/getsentry/sentry-go; opt-in via GLITCHTIP_DSN env var
- Wrap http.ServeMux with sentryhttp middleware for automatic panic recovery
- Rename MinIO bucket defaults: libnovel-chapters→chapters, libnovel-audio→audio,
  libnovel-browse→catalogue (env vars still override)
- Remove staged compiled binaries (backend/bin/runner, backend/healthcheck)

v3/backend/internal/runner/runner.go

@@ -49,9 +49,6 @@ type Config struct {
 	// StaleTaskThreshold is how old a heartbeat must be (or absent) before the
 	// task is considered orphaned and reset to pending. Defaults to 2m when 0.
 	StaleTaskThreshold time.Duration
-	// BrowseRefreshInterval is how often the runner pre-fetches browse page
-	// snapshots from novelfire.net and stores them in MinIO. Defaults to 6h.
-	BrowseRefreshInterval time.Duration
 	// CatalogueRefreshInterval is how often the runner walks the full catalogue,
 	// scrapes per-book metadata, downloads covers, and re-indexes everything in
 	// Meilisearch. Defaults to 24h (expensive — full catalogue walk).
@@ -76,10 +73,7 @@ type Dependencies struct {
 	BookReader bookstore.BookReader
 	// AudioStore persists generated audio and checks key existence.
 	AudioStore bookstore.AudioStore
-	// BrowseStore stores browse page snapshots in MinIO.
-	BrowseStore bookstore.BrowseStore
 	// CoverStore stores book cover images in MinIO.
-	// If nil, cover downloads are skipped during catalogue refresh.
 	CoverStore bookstore.CoverStore
 	// SearchIndex indexes books in Meilisearch after scraping.
 	// If nil a no-op is used.
@@ -125,9 +119,6 @@ func New(cfg Config, deps Dependencies) *Runner {
 	if cfg.StaleTaskThreshold <= 0 {
 		cfg.StaleTaskThreshold = 2 * time.Minute
 	}
-	if cfg.BrowseRefreshInterval <= 0 {
-		cfg.BrowseRefreshInterval = 6 * time.Hour
-	}
 	if cfg.CatalogueRefreshInterval <= 0 {
 		cfg.CatalogueRefreshInterval = 24 * time.Hour
 	}
@@ -151,7 +142,6 @@ func (r *Runner) Run(ctx context.Context) error {
 		"poll_interval", r.cfg.PollInterval,
 		"max_scrape", r.cfg.MaxConcurrentScrape,
 		"max_audio", r.cfg.MaxConcurrentAudio,
-		"browse_refresh_interval", r.cfg.BrowseRefreshInterval,
 		"catalogue_refresh_interval", r.cfg.CatalogueRefreshInterval,
 		"metrics_addr", r.cfg.MetricsAddr,
 	)
@@ -173,14 +163,9 @@ func (r *Runner) Run(ctx context.Context) error {
 	tick := time.NewTicker(r.cfg.PollInterval)
 	defer tick.Stop()
 
-	browseTick := time.NewTicker(r.cfg.BrowseRefreshInterval)
-	defer browseTick.Stop()
-
 	catalogueTick := time.NewTicker(r.cfg.CatalogueRefreshInterval)
 	defer catalogueTick.Stop()
 
-	// Run one browse refresh immediately on startup.
-	go r.runBrowseRefresh(ctx)
 	// Run one catalogue refresh immediately on startup (unless skipped by flag).
 	if !r.cfg.SkipInitialCatalogueRefresh {
 		go r.runCatalogueRefresh(ctx)
@@ -207,8 +192,6 @@ func (r *Runner) Run(ctx context.Context) error {
 				r.deps.Log.Warn("runner: drain timeout exceeded, forcing exit")
 			}
 			return nil
-		case <-browseTick.C:
-			go r.runBrowseRefresh(ctx)
 		case <-catalogueTick.C:
 			go r.runCatalogueRefresh(ctx)
 		case <-tick.C: