add: live encode progress tracking and read-only status web UI

Stream ffmpeg -progress during the video encode into an in-memory tracker
(internal/status) so the long-running step is no longer a black box: percent,
fps, speed, and ETA are derived from the source duration and updated ~1/s.
Progress prints to stdout only (no logs.db row) to avoid burying real events.

Expose it over HTTP (internal/server, default :8080, set http_addr to "" to
disable): GET /status returns the live snapshot, the pending input queue, and
recent non-debug events; GET / serves an embedded dashboard that polls /status
every second. The server shuts down on the same SIGINT/SIGTERM context as the
watcher.

cmd/videnc/main.go

@@ -6,18 +6,22 @@ import (
 	"encoding/hex"
 	"flag"
 	"fmt"
+	"net/http"
 	"os"
 	"os/signal"
 	"path/filepath"
 	"regexp"
 	"strings"
 	"syscall"
+	"time"
 
 	"videnc-vibe/internal/config"
 	"videnc-vibe/internal/encoder"
 	"videnc-vibe/internal/logger"
 	"videnc-vibe/internal/metadata"
 	"videnc-vibe/internal/mover"
+	"videnc-vibe/internal/server"
+	"videnc-vibe/internal/status"
 	"videnc-vibe/internal/watcher"
 	"videnc-vibe/pkg/types"
 )
@@ -53,7 +57,8 @@ func main() {
 	}
 	defer log.Close()
 
-	enc := encoder.New(log)
+	tracker := status.New()
+	enc := encoder.New(log, tracker)
 	if err := enc.CheckDeps(); err != nil {
 		log.Error("Dependency check failed", err.Error())
 		fmt.Fprintf(os.Stderr, "Dependency check failed: %v\n", err)
@@ -65,17 +70,38 @@ func main() {
 	ctx, cancel := signal.NotifyContext(context.Background(), syscall.SIGINT, syscall.SIGTERM)
 	defer cancel()
 
+	if addr := *cfg.HTTPAddr; addr != "" {
+		srv := &http.Server{Addr: addr, Handler: server.New(tracker, log, cfg.Paths.Input).Handler()}
+		go func() {
+			log.Info(fmt.Sprintf("Status server listening on %s", addr))
+			if err := srv.ListenAndServe(); err != nil && err != http.ErrServerClosed {
+				log.Error("Status server", err.Error())
+			}
+		}()
+		go func() {
+			<-ctx.Done()
+			shutCtx, shutCancel := context.WithTimeout(context.Background(), 5*time.Second)
+			defer shutCancel()
+			_ = srv.Shutdown(shutCtx)
+		}()
+	}
+
 	w := watcher.New(cfg.Paths.Input, 15)
 	w.Start(ctx, func(ctx context.Context, inputPath string) error {
-		return processFile(ctx, inputPath, cfg, enc, metaClient, log)
+		return processFile(ctx, inputPath, cfg, enc, metaClient, log, tracker)
 	})
 
 	log.Info("videnc-vibe started")
 }
 
-func processFile(ctx context.Context, inputPath string, cfg *types.Config, enc *encoder.Encoder, metaClient *metadata.Client, log *logger.Logger) error {
+func processFile(ctx context.Context, inputPath string, cfg *types.Config, enc *encoder.Encoder, metaClient *metadata.Client, log *logger.Logger, tracker *status.Tracker) error {
 	log.Info(fmt.Sprintf("Processing: %s", inputPath))
 
+	// Mark this file as the active job (phase: probing) and clear the tracker
+	// back to idle on every exit path — success, failure, or cancellation.
+	tracker.Begin(inputPath)
+	defer tracker.Idle()
+
 	filename := filepath.Base(inputPath)
 	isSeries, imdbID, tvmazeID, season, episode := metadata.ParseFilename(filename)