feat: inject build version/commit into scraper and UI at docker build time

- Go scraper: Version/Commit vars in main.go, injected via -ldflags; Server struct + New() updated; GET /health and new GET /api/version expose them
- UI Dockerfile: ARG BUILD_VERSION/BUILD_COMMIT → ENV PUBLIC_BUILD_VERSION/PUBLIC_BUILD_COMMIT for SvelteKit
- Footer: shows version+short commit when not 'dev' (text-zinc-800, subtle)
- docker-compose: args blocks for scraper and ui build sections pass $GIT_TAG/$GIT_COMMIT

scraper/internal/server/server.go

@@ -43,6 +43,8 @@ type Server struct {
 	running     bool
 	kokoroURL   string // Kokoro-FastAPI base URL, e.g. http://kokoro:8880
 	kokoroVoice string // default voice, e.g. af_bella
+	version     string // semver tag, e.g. "v1.2.3" (set via ldflags)
+	commit      string // short git SHA (set via ldflags)
 
 	// voiceMu guards cachedVoices.
 	voiceMu      sync.RWMutex
@@ -74,7 +76,7 @@ type browseCacheEntry struct {
 }
 
 // New creates a new Server.
-func New(addr string, oCfg orchestrator.Config, novel scraper.NovelScraper, log *slog.Logger, store storage.Store, kokoroURL, kokoroVoice string) *Server {
+func New(addr string, oCfg orchestrator.Config, novel scraper.NovelScraper, log *slog.Logger, store storage.Store, kokoroURL, kokoroVoice, version, commit string) *Server {
 	return &Server{
 		addr:           addr,
 		oCfg:           oCfg,
@@ -83,6 +85,8 @@ func New(addr string, oCfg orchestrator.Config, novel scraper.NovelScraper, log
 		store:          store,
 		kokoroURL:      kokoroURL,
 		kokoroVoice:    kokoroVoice,
+		version:        version,
+		commit:         commit,
 		audioJobIDs:    make(map[string]string),
 		browseInFlight: make(map[string]struct{}),
 		browseMemCache: make(map[string]browseCacheEntry),
@@ -138,6 +142,7 @@ func (s *Server) voices() []string {
 func (s *Server) ListenAndServe(ctx context.Context) error {
 	mux := http.NewServeMux()
 	mux.HandleFunc("GET /health", s.handleHealth)
+	mux.HandleFunc("GET /api/version", s.handleVersion)
 	mux.HandleFunc("POST /scrape", s.handleScrapeCatalogue)
 	mux.HandleFunc("POST /scrape/book", s.handleScrapeBook)
 	mux.HandleFunc("POST /scrape/book/range", s.handleScrapeBookRange)
@@ -222,7 +227,19 @@ func (s *Server) ListenAndServe(ctx context.Context) error {
 
 func (s *Server) handleHealth(w http.ResponseWriter, _ *http.Request) {
 	w.Header().Set("Content-Type", "application/json")
-	_ = json.NewEncoder(w).Encode(map[string]string{"status": "ok"})
+	_ = json.NewEncoder(w).Encode(map[string]string{
+		"status":  "ok",
+		"version": s.version,
+		"commit":  s.commit,
+	})
+}
+
+func (s *Server) handleVersion(w http.ResponseWriter, _ *http.Request) {
+	w.Header().Set("Content-Type", "application/json")
+	_ = json.NewEncoder(w).Encode(map[string]string{
+		"version": s.version,
+		"commit":  s.commit,
+	})
 }
 
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