feat(translation): machine translation pipeline + admin bulk enqueue UI

- LibreTranslate client (chunks on blank lines, ≤4500 chars, 3-goroutine semaphore)
- Runner translation task loop (OTel, heartbeat, MinIO storage)
- PocketBase translation_jobs collection support (create/claim/finish/list)
- Per-chapter language switcher on chapter reader (EN/RU/ID/PT/FR, polls until done)
- Admin /admin/translation page: bulk enqueue form + live-polling jobs table
- New backend routes: POST /api/translation/{slug}/{n}, GET /api/translation/status,
  GET /api/translation/{slug}/{n}, GET /api/admin/translation/jobs,
  POST /api/admin/translation/bulk
- ListTranslationTasks added to taskqueue.Reader interface + store impl
- All builds and tests pass; svelte-check: 0 errors

backend/cmd/backend/main.go

@@ -150,18 +150,19 @@ func run() error {
 			Commit:       commit,
 		},
 		backend.Dependencies{
-			BookReader:    store,
-			RankingStore:  store,
-			AudioStore:    store,
-			PresignStore:  store,
-			ProgressStore: store,
-			CoverStore:    store,
-			Producer:      producer,
-			TaskReader:    store,
-			SearchIndex:   searchIndex,
-			Kokoro:        kokoroClient,
-			PocketTTS:     pocketTTSClient,
-			Log:           log,
+			BookReader:       store,
+			RankingStore:     store,
+			AudioStore:       store,
+			TranslationStore: store,
+			PresignStore:     store,
+			ProgressStore:    store,
+			CoverStore:       store,
+			Producer:         producer,
+			TaskReader:       store,
+			SearchIndex:      searchIndex,
+			Kokoro:           kokoroClient,
+			PocketTTS:        pocketTTSClient,
+			Log:              log,
 		},
 	)
 

backend/cmd/runner/main.go

@@ -24,6 +24,7 @@ import (
 	"github.com/libnovel/backend/internal/browser"
 	"github.com/libnovel/backend/internal/config"
 	"github.com/libnovel/backend/internal/kokoro"
+	"github.com/libnovel/backend/internal/libretranslate"
 	"github.com/libnovel/backend/internal/meili"
 	"github.com/libnovel/backend/internal/novelfire"
 	"github.com/libnovel/backend/internal/otelsetup"
@@ -128,6 +129,14 @@ func run() error {
 		log.Warn("POCKET_TTS_URL not set — pocket-tts voice tasks will fail")
 	}
 
+	// ── LibreTranslate ──────────────────────────────────────────────────────
+	ltClient := libretranslate.New(cfg.LibreTranslate.URL, cfg.LibreTranslate.APIKey)
+	if ltClient != nil {
+		log.Info("libretranslate enabled", "url", cfg.LibreTranslate.URL)
+	} else {
+		log.Info("LIBRETRANSLATE_URL not set — machine translation disabled")
+	}
+
 	// ── Meilisearch ─────────────────────────────────────────────────────────
 	var searchIndex meili.Client
 	if cfg.Meilisearch.URL != "" {
@@ -149,6 +158,7 @@ func run() error {
 		PollInterval:                cfg.Runner.PollInterval,
 		MaxConcurrentScrape:         cfg.Runner.MaxConcurrentScrape,
 		MaxConcurrentAudio:          cfg.Runner.MaxConcurrentAudio,
+		MaxConcurrentTranslation:    cfg.Runner.MaxConcurrentTranslation,
 		OrchestratorWorkers:         workers,
 		MetricsAddr:                 cfg.Runner.MetricsAddr,
 		CatalogueRefreshInterval:    cfg.Runner.CatalogueRefreshInterval,
@@ -170,16 +180,18 @@ func run() error {
 	}
 
 	deps := runner.Dependencies{
-		Consumer:    consumer,
-		BookWriter:  store,
-		BookReader:  store,
-		AudioStore:  store,
-		CoverStore:  store,
-		SearchIndex: searchIndex,
-		Novel:       novel,
-		Kokoro:      kokoroClient,
-		PocketTTS:   pocketTTSClient,
-		Log:         log,
+		Consumer:         consumer,
+		BookWriter:       store,
+		BookReader:       store,
+		AudioStore:       store,
+		CoverStore:       store,
+		TranslationStore: store,
+		SearchIndex:      searchIndex,
+		Novel:            novel,
+		Kokoro:           kokoroClient,
+		PocketTTS:        pocketTTSClient,
+		LibreTranslate:   ltClient,
+		Log:              log,
 	}
 	r := runner.New(rCfg, deps)