fix-2

cmd/unified/main.go

@@ -10,6 +10,7 @@ import (
 	"net/http"
 	"os"
 	"os/signal"
+	"path/filepath"
 	"strconv"
 	"strings"
 	"syscall"
@@ -22,6 +23,14 @@ import (
 	"git.send.nrw/sendnrw/decent-webui/internal/mesh"
 )
 
+func parseDuration(s string, def time.Duration) time.Duration {
+	d, err := time.ParseDuration(strings.TrimSpace(s))
+	if err != nil || d <= 0 {
+		return def
+	}
+	return d
+}
+
 /*** Config ***/
 func loadConfig() AppConfig {
 	// HTTP
@@ -44,6 +53,14 @@ func loadConfig() AppConfig {
 		DiscoveryAddress: getenvDefault("MESH_DISCOVERY_ADDR", "239.8.8.8:9898"),
 	}
 
+	m.PeerTTL = parseDuration(os.Getenv("MESH_PEER_TTL"), 2*time.Minute)
+	m.PruneInterval = parseDuration(os.Getenv("MESH_PRUNE_INTERVAL"), 30*time.Second)
+
+	m.HelloInterval = parseDuration(os.Getenv("MESH_HELLO_INTERVAL"), 20*time.Second)
+	m.HelloFanout = parseIntEnv(os.Getenv("MESH_HELLO_FANOUT"), 8)
+
+	m.BlobTimeout = parseDuration(os.Getenv("MESH_BLOB_TIMEOUT"), 0)
+
 	// Wenn keine AdvertURL gesetzt ist, versuche eine sinnvolle Herleitung:
 	if strings.TrimSpace(m.AdvertURL) == "" {
 		m.AdvertURL = inferAdvertURL(m.BindAddr)
@@ -62,11 +79,13 @@ func loadConfig() AppConfig {
 	}
 
 	return AppConfig{
-		HTTPAddr:  httpAddr,
-		APIKey:    apiKey,
-		AdminUser: adminUser,
-		AdminPass: adminPass,
-		Mesh:      m,
+		HTTPAddr:        httpAddr,
+		APIKey:          apiKey,
+		AdminUser:       adminUser,
+		AdminPass:       adminPass,
+		Mesh:            m,
+		PublicDownloads: parseBoolEnv("PUBLIC_DOWNLOADS", false),
+		PublicPath:      getenvDefault("PUBLIC_DOWNLOAD_PATH", "/dl"),
 	}
 }
 
@@ -88,6 +107,18 @@ func parseBoolEnv(k string, def bool) bool {
 	return v == "1" || v == "true" || v == "yes" || v == "on"
 }
 
+func parseIntEnv(k string, def int) int {
+	v := strings.TrimSpace(os.Getenv(k))
+	if v == "" {
+		return def
+	}
+	n, err := strconv.Atoi(v)
+	if err != nil {
+		return def
+	}
+	return n
+}
+
 func splitCSV(s string) []string {
 	s = strings.TrimSpace(s)
 	if s == "" {
@@ -137,6 +168,9 @@ type AppConfig struct {
 	AdminUser string
 	AdminPass string
 	Mesh      mesh.Config
+
+	PublicDownloads bool   // ENV: PUBLIC_DOWNLOADS (default false)
+	PublicPath      string // ENV: PUBLIC_DOWNLOAD_PATH (default "/dl")
 }
 
 /*** Middleware ***/
@@ -188,7 +222,7 @@ func writeJSON(w http.ResponseWriter, code int, v any) {
 
 /*** API-Routen ***/
 
-func fileRoutes(mux *http.ServeMux, store filesvc.MeshStore) {
+func fileRoutes(mux *http.ServeMux, store filesvc.MeshStore, blobs blobfs.Store) {
 	// Health
 	mux.HandleFunc("/api/v1/health", func(w http.ResponseWriter, r *http.Request) {
 		writeJSON(w, http.StatusOK, map[string]string{"status": "ok"})
@@ -198,13 +232,8 @@ func fileRoutes(mux *http.ServeMux, store filesvc.MeshStore) {
 	mux.HandleFunc("/api/v1/items", func(w http.ResponseWriter, r *http.Request) {
 		switch r.Method {
 		case http.MethodGet:
-			nextStr := r.URL.Query().Get("next")
-			var next filesvc.ID
-			if nextStr != "" {
-				if n, err := strconv.ParseInt(nextStr, 10, 64); err == nil {
-					next = filesvc.ID(n)
-				}
-			}
+			nextStr := strings.TrimSpace(r.URL.Query().Get("next"))
+			next := filesvc.ID(nextStr)
 			items, nextOut, err := store.List(r.Context(), next, 100)
 			if err != nil {
 				writeJSON(w, http.StatusInternalServerError, map[string]string{"error": err.Error()})
@@ -246,6 +275,10 @@ func fileRoutes(mux *http.ServeMux, store filesvc.MeshStore) {
 		}
 		it, err := store.Rename(r.Context(), in.ID, in.Name)
 		if err != nil {
+			if errors.Is(err, filesvc.ErrForbidden) {
+				writeJSON(w, http.StatusForbidden, map[string]string{"error": "only owner may modify"})
+				return
+			}
 			status := http.StatusBadRequest
 			if errors.Is(err, filesvc.ErrNotFound) {
 				status = http.StatusNotFound
@@ -270,7 +303,12 @@ func fileRoutes(mux *http.ServeMux, store filesvc.MeshStore) {
 			return
 		}
 		it, err := store.Delete(r.Context(), in.ID)
+		_ = blobs.Delete(r.Context(), string(in.ID))
 		if err != nil {
+			if errors.Is(err, filesvc.ErrForbidden) {
+				writeJSON(w, http.StatusForbidden, map[string]string{"error": "only owner may modify"})
+				return
+			}
 			status := http.StatusBadRequest
 			if errors.Is(err, filesvc.ErrNotFound) {
 				status = http.StatusNotFound
@@ -310,7 +348,7 @@ func apiFiles(mux *http.ServeMux, store filesvc.MeshStore, blobs blobfs.Store, m
 			writeJSON(w, http.StatusBadRequest, map[string]string{"error": err.Error()})
 			return
 		}
-		meta, err := blobs.Save(r.Context(), int64(it.ID), name, fh)
+		meta, err := blobs.Save(r.Context(), string(it.ID), name, fh)
 		if err != nil {
 			_, _ = store.Delete(r.Context(), it.ID)
 			writeJSON(w, http.StatusInternalServerError, map[string]string{"error": err.Error()})
@@ -325,27 +363,61 @@ func apiFiles(mux *http.ServeMux, store filesvc.MeshStore, blobs blobfs.Store, m
 
 	// Download
 	mux.HandleFunc("/api/v1/files/", func(w http.ResponseWriter, r *http.Request) {
-		// /api/v1/files/{id}/download
 		parts := strings.Split(strings.TrimPrefix(r.URL.Path, "/api/v1/files/"), "/")
 		if len(parts) != 2 || parts[1] != "download" {
 			http.NotFound(w, r)
 			return
 		}
-		id, err := strconv.ParseInt(parts[0], 10, 64)
+		id := parts[0]
+		if strings.TrimSpace(id) == "" {
+			http.NotFound(w, r)
+			return
+		}
+
+		// 1) Metadaten prüfen
+		it, err := store.Get(r.Context(), filesvc.ID(id))
+		if err != nil || it.Deleted {
+			http.NotFound(w, r)
+			return
+		}
+
+		// 2) lokal
+		if rc, meta, err := blobs.Open(r.Context(), id); err == nil {
+			defer rc.Close()
+			serveBlob(w, r, rc, meta, it.Name)
+			return
+		}
+
+		// 3) remote holen & cachen
+		it1, _ := store.Get(r.Context(), filesvc.ID(id))
+		peers := meshNode.PeerList()
+		ttl := 2 * time.Minute
+		if cfg := meshNode.Config(); cfg.PeerTTL > 0 {
+			ttl = cfg.PeerTTL
+		}
+		if !isOwnerActive(it1.Owner, peers, ttl) {
+			http.NotFound(w, r)
+			return
+		}
+		rrc, _, _, _, err := meshNode.FetchBlobAny(r.Context(), id)
 		if err != nil {
 			http.NotFound(w, r)
 			return
 		}
-		rc, meta, err := blobs.Open(r.Context(), id)
-		if err != nil {
-			http.NotFound(w, r)
+		defer rrc.Close()
+		if _, err := blobs.Save(r.Context(), id, it1.Name, rrc); err != nil {
+			http.Error(w, "cache failed", http.StatusInternalServerError)
 			return
 		}
-		defer rc.Close()
-		w.Header().Set("Content-Type", meta.ContentType)
-		w.Header().Set("Content-Length", strconv.FormatInt(meta.Size, 10))
-		w.Header().Set("Content-Disposition", fmt.Sprintf(`attachment; filename="%s"`, meta.Name))
-		_, _ = io.Copy(w, rc)
+
+		// 4) lokal streamen
+		lrc, meta, err := blobs.Open(r.Context(), id)
+		if err != nil {
+			http.Error(w, "open failed", http.StatusInternalServerError)
+			return
+		}
+		defer lrc.Close()
+		serveBlob(w, r, lrc, meta, it1.Name)
 	})
 }
 
@@ -355,10 +427,11 @@ func toMeshSnapshot(s filesvc.Snapshot) mesh.Snapshot {
 	out := mesh.Snapshot{Items: make([]mesh.Item, 0, len(s.Items))}
 	for _, it := range s.Items {
 		out.Items = append(out.Items, mesh.Item{
-			ID:        int64(it.ID),
+			ID:        it.ID,
 			Name:      it.Name,
 			UpdatedAt: it.UpdatedAt,
 			Deleted:   it.Deleted,
+			Owner:     it.Owner,
 		})
 	}
 	return out
@@ -368,26 +441,58 @@ func fromMeshSnapshot(ms mesh.Snapshot) filesvc.Snapshot {
 	out := filesvc.Snapshot{Items: make([]filesvc.File, 0, len(ms.Items))}
 	for _, it := range ms.Items {
 		out.Items = append(out.Items, filesvc.File{
-			ID:        filesvc.ID(it.ID),
+			ID:        it.ID,
 			Name:      it.Name,
 			UpdatedAt: it.UpdatedAt,
 			Deleted:   it.Deleted,
+			Owner:     it.Owner,
 		})
 	}
 	return out
 }
 
+// isOwnerActive prüft, ob der Owner in der Peer-Liste als "aktiv" gilt.
+func isOwnerActive(owner string, peers []mesh.Peer, ttl time.Duration) bool {
+	owner = strings.TrimSpace(owner)
+	if owner == "" {
+		return true
+	}
+	cutoff := time.Now().Add(-ttl)
+	for _, p := range peers {
+		if strings.TrimSpace(p.URL) != owner {
+			continue
+		}
+		// Self ist per Definition aktiv
+		if p.Self {
+			return true
+		}
+		// ohne LastSeen: als inaktiv behandeln
+		if p.LastSeen.IsZero() {
+			return false
+		}
+		return p.LastSeen.After(cutoff)
+	}
+	// Owner ist nicht mal in der Liste: inaktiv
+	return false
+}
+
 /*** main ***/
 
 func main() {
 	cfg := loadConfig()
 
 	// Domain-Store (mesh-fähig)
-	st := filesvc.NewMemStore()
+	nodeID := strings.TrimSpace(cfg.Mesh.AdvertURL)
+	//st := filesvc.NewMemStore(nodeID)
 
 	// Mesh starten
-	mcfg := mesh.FromEnv()
-	mnode, err := mesh.New(mcfg, mesh.Callbacks{
+	//mcfg := mesh.FromEnv()
+	blobs := blobfs.New(getenvDefault("DATA_DIR", "./data"))
+	dataDir := getenvDefault("DATA_DIR", "./data")
+	metaPath := filepath.Join(dataDir, "meta", "items.json")
+	st := filesvc.NewMemStorePersistent(nodeID, metaPath)
+
+	mnode, err := mesh.New(cfg.Mesh, mesh.Callbacks{
 		GetSnapshot: func(ctx context.Context) (mesh.Snapshot, error) {
 			s, err := st.Snapshot(ctx)
 			if err != nil {
@@ -398,28 +503,88 @@ func main() {
 		ApplyRemote: func(ctx context.Context, s mesh.Snapshot) error {
 			return st.ApplyRemote(ctx, fromMeshSnapshot(s))
 		},
+		BlobOpen: func(ctx context.Context, id string) (io.ReadCloser, string, string, int64, error) { //5588
+			it, err := st.Get(ctx, filesvc.ID(id))
+			if err != nil || it.Deleted {
+				return nil, "", "", 0, fmt.Errorf("not found")
+			}
+			rc, meta, err := blobs.Open(ctx, id)
+			if err != nil {
+				return nil, "", "", 0, err
+			}
+			return rc, it.Name, meta.ContentType, meta.Size, nil
+		},
 	})
 	if err != nil {
 		log.Fatalf("mesh init: %v", err)
 	}
+
+	// Hintergrund-Pruner starten
+	mnode.StartPeerPruner()
+
 	go func() {
 		log.Printf("[mesh] listening on %s advertise %s seeds=%v discovery=%v",
-			mcfg.BindAddr, mcfg.AdvertURL, mcfg.Seeds, mcfg.EnableDiscovery)
+			cfg.Mesh.BindAddr, cfg.Mesh.AdvertURL, cfg.Mesh.Seeds, cfg.Mesh.EnableDiscovery)
 		if err := mnode.Serve(); err != nil && !errors.Is(err, http.ErrServerClosed) {
 			log.Fatalf("mesh serve: %v", err)
 		}
 	}()
 
+	go func() {
+		ticker := time.NewTicker(1 * time.Minute)
+		defer ticker.Stop()
+		for range ticker.C {
+			// aktive Owner bestimmen
+			peers := mnode.PeerList()
+			ttl := 2 * time.Minute
+			if cfg := mnode.Config(); cfg.PeerTTL > 0 {
+				ttl = cfg.PeerTTL
+			}
+			cutoff := time.Now().Add(-ttl)
+
+			active := map[string]bool{}
+			for _, p := range peers {
+				if p.Self {
+					active[p.URL] = true
+					continue
+				}
+				if !p.LastSeen.IsZero() && p.LastSeen.After(cutoff) {
+					active[p.URL] = true
+				}
+			}
+
+			// alle Items durchgehen; Blobs von Offline-Ownern löschen
+			var next filesvc.ID
+			for {
+				items, nextOut, _ := st.List(context.Background(), next, 1000)
+				for _, it := range items {
+					if it.Owner == "" || active[it.Owner] {
+						continue
+					}
+					_ = blobs.Delete(context.Background(), it.ID)
+				}
+				if nextOut == "" {
+					break
+				}
+				next = nextOut
+			}
+		}
+	}()
+
 	// Root-Mux
 	root := http.NewServeMux()
 
 	// API (Bearer-Auth)
-	blobs := blobfs.New(getenvDefault("DATA_DIR", "./data"))
+	//blobs := blobfs.New(getenvDefault("DATA_DIR", "./data"))
 	apiMux := http.NewServeMux()
-	fileRoutes(apiMux, st)
+	fileRoutes(apiMux, st, blobs)
 	apiFiles(apiMux, st, blobs, mnode)
 	root.Handle("/api/", authMiddleware(cfg.APIKey, apiMux))
 
+	if cfg.PublicDownloads {
+		registerPublicDownloads(root, st, blobs, mnode, cfg.PublicPath)
+	}
+
 	// Admin-UI (optional BasicAuth via ADMIN_USER/ADMIN_PASS)
 	adminRoot := http.NewServeMux()
 	admin.Register(adminRoot, admin.Deps{Store: st, Mesh: mnode, Blob: blobs})
@@ -450,7 +615,8 @@ func main() {
 
 	// Graceful shutdown
 	go func() {
-		log.Printf("http listening on %s (api=/api/v1, admin=/admin)", cfg.Mesh.BindAddr)
+		log.Printf("http listening on %s (api=/api/v1, admin=/admin)", cfg.HTTPAddr)
+		log.Printf("mesh listening on %s", cfg.Mesh.BindAddr)
 		if err := srv.ListenAndServe(); err != nil && !errors.Is(err, http.ErrServerClosed) {
 			log.Fatalf("http server: %v", err)
 		}
@@ -467,3 +633,96 @@ func main() {
 	_ = mnode.Close(ctx)
 	log.Println("shutdown complete")
 }
+
+// Public: GET {base}/{id}
+// Beispiel: /dl/1
+func registerPublicDownloads(mux *http.ServeMux, store filesvc.MeshStore, blobs blobfs.Store, meshNode *mesh.Node, base string) {
+	if !strings.HasPrefix(base, "/") {
+		base = "/" + base
+	}
+	mux.HandleFunc(base+"/", func(w http.ResponseWriter, r *http.Request) {
+		id := strings.TrimSpace(strings.TrimPrefix(r.URL.Path, base+"/"))
+		if id == "" {
+			http.NotFound(w, r)
+			return
+		}
+
+		// 1) Metadaten prüfen
+		it, err := store.Get(r.Context(), filesvc.ID(id))
+		if err != nil || it.Deleted {
+			http.NotFound(w, r)
+			return
+		}
+
+		// 2) Lokal versuchen
+		if rc, meta, err := blobs.Open(context.Background(), id); err == nil {
+			defer rc.Close()
+			serveBlob(w, r, rc, meta, it.Name)
+			return
+		}
+
+		// (Optional) Owner-Online-Check — wenn du auch bei offline Ownern liefern willst, block auskommentieren
+		{
+			peers := meshNode.PeerList()
+			ttl := 2 * time.Minute
+			if !isOwnerActive(it.Owner, peers, ttl) {
+				http.NotFound(w, r)
+				return
+			}
+		}
+
+		// 3) Aus Mesh holen — EIGENER Timeout-Kontext, NICHT r.Context()
+		rrc, remoteName, _, _, err := meshNode.FetchBlobAny(context.Background(), id)
+		if err != nil {
+			http.NotFound(w, r)
+			return
+		}
+		defer rrc.Close()
+
+		filename := strings.TrimSpace(remoteName)
+		if filename == "" {
+			filename = it.Name
+		}
+
+		// 4) Lokal cachen — KEIN Request-Kontext, damit Save nicht abbricht
+		if _, err := blobs.Save(context.Background(), id, filename, rrc); err != nil {
+			log.Printf("[public] cache save failed id=%s name=%q: %v", id, filename, err)
+			http.Error(w, "cache failed: "+err.Error(), http.StatusInternalServerError)
+			return
+		}
+
+		// 5) Erneut lokal öffnen und streamen
+		lrc, meta, err := blobs.Open(context.Background(), id)
+		if err != nil {
+			http.Error(w, "open failed: "+err.Error(), http.StatusInternalServerError)
+			return
+		}
+		defer lrc.Close()
+		serveBlob(w, r, lrc, meta, filename)
+	})
+}
+
+// Hilfsfunktion: setzt sinnvolle Header und streamt die Datei
+func serveBlob(w http.ResponseWriter, r *http.Request, rc io.ReadSeeker, meta blobfs.Meta, downloadName string) {
+	if meta.SHA256 != "" {
+		etag := `W/"` + meta.SHA256 + `"`
+		if r.Header.Get("If-None-Match") == etag {
+			w.WriteHeader(http.StatusNotModified)
+			return
+		}
+		w.Header().Set("ETag", etag)
+	}
+	if meta.ContentType == "" {
+		meta.ContentType = "application/octet-stream"
+	}
+	if downloadName == "" {
+		downloadName = meta.Name
+	}
+
+	w.Header().Set("Content-Type", meta.ContentType)
+	w.Header().Set("Content-Length", strconv.FormatInt(meta.Size, 10))
+	w.Header().Set("Content-Disposition", fmt.Sprintf(`attachment; filename="%s"`, downloadName))
+	w.Header().Set("Access-Control-Expose-Headers", "Content-Disposition")
+	w.Header().Set("X-Robots-Tag", "noindex")
+	_, _ = io.Copy(w, rc)
+}

internal/admin/admin.go

@@ -56,31 +56,36 @@ func Register(mux *http.ServeMux, d Deps) {
 
 	// Partials
 	mux.HandleFunc("/admin/items", func(w http.ResponseWriter, r *http.Request) {
-		nextQ := strings.TrimSpace(r.URL.Query().Get("next"))
-		var nextID filesvc.ID
-		if nextQ != "" {
-			if n, err := strconv.ParseInt(nextQ, 10, 64); err == nil {
-				nextID = filesvc.ID(n)
-			}
-		}
+		nextID := filesvc.ID(strings.TrimSpace(r.URL.Query().Get("next")))
 		items, nextOut, _ := d.Store.List(r.Context(), nextID, 100)
 
 		type row struct {
-			ID        int64
-			Name      string
-			UpdatedAt int64
-			HasBlob   bool
-			Size      int64
+			ID          string
+			Name        string
+			UpdatedAt   int64
+			HasBlob     bool
+			Size        int64
+			Owner       string
+			OwnerActive bool
 		}
 		rows := make([]row, 0, len(items))
+
+		peers := d.Mesh.PeerList()
+		ttl := 2 * time.Minute
+		if cfg := d.Mesh.Config(); cfg.PeerTTL > 0 {
+			ttl = cfg.PeerTTL
+		}
+
 		for _, it := range items {
-			meta, ok, _ := d.Blob.Stat(r.Context(), int64(it.ID))
+			meta, ok, _ := d.Blob.Stat(r.Context(), it.ID)
 			rows = append(rows, row{
-				ID:        int64(it.ID),
-				Name:      it.Name,
-				UpdatedAt: it.UpdatedAt,
-				HasBlob:   ok,
-				Size:      meta.Size,
+				ID:          it.ID,
+				Name:        it.Name,
+				UpdatedAt:   it.UpdatedAt,
+				HasBlob:     ok,
+				Size:        meta.Size,
+				Owner:       it.Owner,
+				OwnerActive: isOwnerActive(it.Owner, peers, ttl),
 			})
 		}
 
@@ -90,6 +95,42 @@ func Register(mux *http.ServeMux, d Deps) {
 		})
 	})
 
+	mux.HandleFunc("/admin/items/takeover", func(w http.ResponseWriter, r *http.Request) {
+		if r.Method != http.MethodPost {
+			http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
+			return
+		}
+		id := strings.TrimSpace(r.FormValue("id"))
+		if id != "" {
+			// Nur zulassen, wenn Owner tatsächlich offline ist
+			it, err := d.Store.Get(r.Context(), filesvc.ID(id))
+			if err == nil {
+				peers := d.Mesh.PeerList()
+				ttl := 2 * time.Minute
+				if cfg := d.Mesh.Config(); cfg.PeerTTL > 0 {
+					ttl = cfg.PeerTTL
+				}
+				if !isOwnerActive(it.Owner, peers, ttl) {
+					// eigene URL aus PeerList ermitteln
+					self := ""
+					for _, p := range peers {
+						if p.Self {
+							self = p.URL
+							break
+						}
+					}
+					if self == "" {
+						self = "unknown-self"
+					}
+					if _, err := d.Store.TakeoverOwner(r.Context(), filesvc.ID(id), self); err == nil {
+						_ = d.Mesh.SyncNow(r.Context())
+					}
+				}
+			}
+		}
+		renderItemsPartial(w, r, d)
+	})
+
 	// Upload (multipart/form-data, Feldname "file", optional name-Override)
 	mux.HandleFunc("/admin/files/upload", func(w http.ResponseWriter, r *http.Request) {
 		if r.Method != http.MethodPost {
@@ -119,14 +160,14 @@ func Register(mux *http.ServeMux, d Deps) {
 		}
 
 		// 2) Blob speichern
-		if _, err := d.Blob.Save(r.Context(), int64(it.ID), name, fh); err != nil {
+		if _, err := d.Blob.Save(r.Context(), (it.ID), name, fh); err != nil {
 			// zurückrollen (Tombstone)
 			_, _ = d.Store.Delete(r.Context(), it.ID)
 			http.Error(w, "save failed: "+err.Error(), http.StatusInternalServerError)
 			return
 		}
 		_ = d.Mesh.SyncNow(r.Context()) // best-effort Push
-		http.Redirect(w, r, "/admin/items", http.StatusSeeOther)
+		http.Redirect(w, r, "/admin", http.StatusSeeOther)
 	})
 
 	// Download (Admin – BasicAuth schützt ggf.)
@@ -137,21 +178,46 @@ func Register(mux *http.ServeMux, d Deps) {
 			http.NotFound(w, r)
 			return
 		}
-		id, err := strconv.ParseInt(parts[0], 10, 64)
+		id := parts[0]
+		if strings.TrimSpace(id) == "" {
+			http.NotFound(w, r)
+			return
+		}
+
+		// 1) lokal versuchen
+		if rc, meta, err := d.Blob.Open(r.Context(), id); err == nil {
+			defer rc.Close()
+			w.Header().Set("Content-Type", meta.ContentType)
+			w.Header().Set("Content-Length", strconv.FormatInt(meta.Size, 10))
+			w.Header().Set("Content-Disposition", fmt.Sprintf(`attachment; filename="%s"`, meta.Name))
+			_, _ = io.Copy(w, rc)
+			return
+		}
+
+		// 2) Remote über Mesh holen
+		rrc, name, _, _, err := d.Mesh.FetchBlobAny(r.Context(), id)
 		if err != nil {
 			http.NotFound(w, r)
 			return
 		}
-		rc, meta, err := d.Blob.Open(r.Context(), id)
-		if err != nil {
-			http.NotFound(w, r)
+		defer rrc.Close()
+
+		// 3) lokal cachen (Save konsumiert den Stream)
+		if _, err := d.Blob.Save(r.Context(), id, name, rrc); err != nil {
+			http.Error(w, "cache failed: "+err.Error(), http.StatusInternalServerError)
 			return
 		}
-		defer rc.Close()
+		// 4) aus lokalem Store ausliefern (saubere Größe/CT)
+		lrc, meta, err := d.Blob.Open(r.Context(), id)
+		if err != nil {
+			http.Error(w, "open failed", http.StatusInternalServerError)
+			return
+		}
+		defer lrc.Close()
 		w.Header().Set("Content-Type", meta.ContentType)
 		w.Header().Set("Content-Length", strconv.FormatInt(meta.Size, 10))
 		w.Header().Set("Content-Disposition", fmt.Sprintf(`attachment; filename="%s"`, meta.Name))
-		_, _ = io.Copy(w, rc)
+		_, _ = io.Copy(w, lrc)
 	})
 
 	mux.HandleFunc("/admin/peers", func(w http.ResponseWriter, r *http.Request) {
@@ -162,7 +228,7 @@ func Register(mux *http.ServeMux, d Deps) {
 		})
 	})
 
-	// Actions (HTMX POSTs)
+	// CREATE
 	mux.HandleFunc("/admin/items/create", func(w http.ResponseWriter, r *http.Request) {
 		if r.Method != http.MethodPost {
 			http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
@@ -171,36 +237,40 @@ func Register(mux *http.ServeMux, d Deps) {
 		name := strings.TrimSpace(r.FormValue("name"))
 		if name != "" {
 			_, _ = d.Store.Create(r.Context(), name)
-			_ = d.Mesh.SyncNow(r.Context()) // prompt push (best effort)
+			_ = d.Mesh.SyncNow(r.Context())
 		}
-		// Nach Aktion Items partial zurückgeben (HTMX swap)
-		http.Redirect(w, r, "/admin/items", http.StatusSeeOther)
+		// statt Redirect:
+		renderItemsPartial(w, r, d)
 	})
 
+	// RENAME
 	mux.HandleFunc("/admin/items/rename", func(w http.ResponseWriter, r *http.Request) {
 		if r.Method != http.MethodPost {
 			http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
 			return
 		}
-		idStr := r.FormValue("id")
+		id := strings.TrimSpace(r.FormValue("id"))
 		newName := strings.TrimSpace(r.FormValue("name"))
-		if id, err := strconv.ParseInt(idStr, 10, 64); err == nil && newName != "" {
+		if id != "" && newName != "" {
 			_, _ = d.Store.Rename(r.Context(), filesvc.ID(id), newName)
 			_ = d.Mesh.SyncNow(r.Context())
 		}
-		http.Redirect(w, r, "/admin/items", http.StatusSeeOther)
+		renderItemsPartial(w, r, d)
 	})
 
+	// DELETE
 	mux.HandleFunc("/admin/items/delete", func(w http.ResponseWriter, r *http.Request) {
 		if r.Method != http.MethodPost {
 			http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
 			return
 		}
-		if id, err := strconv.ParseInt(r.FormValue("id"), 10, 64); err == nil {
+		id := strings.TrimSpace(r.FormValue("id"))
+		if id != "" {
 			_, _ = d.Store.Delete(r.Context(), filesvc.ID(id))
+			_ = d.Blob.Delete(r.Context(), id)
 			_ = d.Mesh.SyncNow(r.Context())
 		}
-		http.Redirect(w, r, "/admin/items", http.StatusSeeOther)
+		renderItemsPartial(w, r, d)
 	})
 
 	mux.HandleFunc("/admin/mesh/syncnow", func(w http.ResponseWriter, r *http.Request) {
@@ -231,3 +301,61 @@ func BasicAuth(user, pass string, next http.Handler) http.Handler {
 		next.ServeHTTP(w, r)
 	})
 }
+
+// rebuild & render items partial for HTMX swaps
+func renderItemsPartial(w http.ResponseWriter, r *http.Request, d Deps) {
+	type row struct {
+		ID          string
+		Name        string
+		UpdatedAt   int64
+		HasBlob     bool
+		Size        int64
+		Owner       string
+		OwnerActive bool
+	}
+
+	nextID := filesvc.ID(strings.TrimSpace(r.URL.Query().Get("next")))
+	items, nextOut, _ := d.Store.List(r.Context(), nextID, 100)
+
+	peers := d.Mesh.PeerList()
+	ttl := 2 * time.Minute
+
+	rows := make([]row, 0, len(items))
+	for _, it := range items {
+		meta, ok, _ := d.Blob.Stat(r.Context(), (it.ID))
+		rows = append(rows, row{
+			ID:          (it.ID),
+			Name:        it.Name,
+			UpdatedAt:   it.UpdatedAt,
+			HasBlob:     ok,
+			Size:        meta.Size,
+			Owner:       it.Owner,
+			OwnerActive: isOwnerActive(it.Owner, peers, ttl),
+		})
+	}
+	w.Header().Set("Content-Type", "text/html; charset=utf-8")
+	_ = tplItems.Execute(w, map[string]any{
+		"Items": rows,
+		"Next":  nextOut,
+	})
+}
+
+func isOwnerActive(owner string, peers []mesh.Peer, ttl time.Duration) bool {
+	if strings.TrimSpace(owner) == "" {
+		return true
+	}
+	cutoff := time.Now().Add(-ttl)
+	for _, p := range peers {
+		if strings.TrimSpace(p.URL) == strings.TrimSpace(owner) {
+			// Self ist immer aktiv, sonst nach LastSeen
+			if p.Self {
+				return true
+			}
+			if p.LastSeen.IsZero() {
+				return false
+			}
+			return p.LastSeen.After(cutoff)
+		}
+	}
+	return false
+}

internal/admin/tpl/layout.html

@@ -8,7 +8,7 @@
   <style>
     :root { --bg:#0b1220; --card:#121a2b; --muted:#94a3b8; --text:#e5e7eb; --accent:#4f46e5; }
     html,body { margin:0; background:var(--bg); color:var(--text); font-family: ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, Ubuntu; }
-    .wrap { max-width: 980px; margin: 40px auto; padding: 0 16px; }
+    .wrap { max-width: 1200px; margin: 40px auto; padding: 0 16px; }
     .nav { display:flex; gap:12px; margin-bottom:16px; }
     .btn { background:var(--card); border:1px solid #243044; padding:8px 12px; border-radius:10px; color:var(--text); cursor:pointer; }
     .btn:hover { border-color:#3b4a66; }

internal/admin/tpl/partials_items.html

@@ -1,6 +1,6 @@
 <div class="row">
   <div style="flex: 1 1 360px">
-    <form hx-post="/admin/items/create" hx-target="#items" hx-get="/admin/items" hx-swap="outerHTML">
+    <form hx-post="/admin/items/create" hx-target="#items" hx-swap="outerHTML">
       <label>Neue leere Datei (nur Metadaten)</label>
       <div style="display:flex; gap:8px; margin-top:6px">
         <input type="text" name="name" placeholder="z.B. notes.txt" required>
@@ -24,13 +24,19 @@
   <table>
     <thead>
       <tr>
-        <th>ID</th><th>Name</th><th>Updated</th><th>Blob</th><th style="width:260px">Aktionen</th>
+        <th>ID</th>
+        <th>Name</th>
+        <th>Updated</th>
+        <th>Blob</th>
+        <th>Owner</th>
+        <th>Status</th>
+        <th style="width:320px">Aktionen</th>
       </tr>
     </thead>
     <tbody>
     {{ range .Items }}
       <tr>
-        <td>{{ .ID }}</td>
+        <td><code style="font-size:12px">{{ .ID }}</code></td>
         <td>{{ .Name }}</td>
         <td><small class="muted">{{ printf "%.19s" (timeRFC3339 .UpdatedAt) }}</small></td>
         <td>
@@ -41,17 +47,33 @@
             <span class="pill" style="background:#3a0b0b;border-color:#5b1a1a;color:#fbb;">fehlt</span>
           {{ end }}
         </td>
+        <td><small class="muted">{{ .Owner }}</small></td>
         <td>
-          <form style="display:inline-flex; gap:6px" 
-                hx-post="/admin/items/rename" 
-                hx-target="#items" hx-get="/admin/items" hx-swap="outerHTML">
+          {{ if .OwnerActive }}
+            <span class="pill">online</span>
+          {{ else }}
+            <span class="pill" style="background:#5b1a1a;border-color:#7a2b2b;color:#fbb">offline</span>
+            <!-- Owner-Handover nur wenn offline -->
+            <form style="display:inline"
+                  hx-post="/admin/items/takeover"
+                  hx-target="#items" hx-swap="outerHTML"
+                  onsubmit="return confirm('Owner übernehmen?');">
+              <input type="hidden" name="id" value="{{ .ID }}">
+              <button class="btn" type="submit">Übernehmen</button>
+            </form>
+          {{ end }}
+        </td>
+        <td>
+          <form style="display:inline-flex; gap:6px"
+                hx-post="/admin/items/rename"
+                hx-target="#items" hx-swap="outerHTML">
             <input type="hidden" name="id" value="{{ .ID }}">
             <input type="text" name="name" placeholder="Neuer Name">
             <button class="btn" type="submit">Rename</button>
           </form>
-          <form style="display:inline" 
-                hx-post="/admin/items/delete" 
-                hx-target="#items" hx-get="/admin/items" hx-swap="outerHTML"
+          <form style="display:inline"
+                hx-post="/admin/items/delete"
+                hx-target="#items" hx-swap="outerHTML"
                 onsubmit="return confirm('Wirklich löschen (inkl. Blob)?');">
             <input type="hidden" name="id" value="{{ .ID }}">
             <button class="btn" type="submit">Delete</button>
@@ -62,17 +84,17 @@
         </td>
       </tr>
     {{ else }}
-      <tr><td colspan="5" class="muted">Keine Dateien vorhanden.</td></tr>
+      <tr><td colspan="7" class="muted">Keine Dateien vorhanden.</td></tr>
     {{ end }}
     </tbody>
   </table>
 
   {{ if .Next }}
     <div style="margin-top:10px">
-      <button class="btn" 
-              hx-get="/admin/items?next={{ .Next }}" 
+      <button class="btn"
+              hx-get="/admin/items?next={{ .Next }}"
               hx-target="#items" hx-swap="outerHTML">Mehr laden</button>
       <span class="pill">next={{ .Next }}</span>
     </div>
   {{ end }}
-</div>
+</div>

internal/admin/tpl/partials_peers.html

@@ -11,11 +11,11 @@
     {{ range .Peers }}
       <tr>
         <td>{{ .URL }}</td>
-        <td>{{ if .Self }}✅{{ else }}—{{ end }}</td>
+        <td>{{ if .Self }}✅{{ else }}🔗{{ end }}</td>
         <td><small class="muted">{{ .LastSeen }}</small></td>
       </tr>
     {{ else }}
-      <tr><td colspan="3" class="muted">Keine Peers vorhanden.</td></tr>
+      <tr><td colspan="3" class="muted">⚠️ Keine Peers vorhanden.</td></tr>
     {{ end }}
     </tbody>
   </table>

internal/blobfs/blobfs.go

@@ -6,7 +6,6 @@ import (
 	"encoding/hex"
 	"encoding/json"
 	"errors"
-	"fmt"
 	"io"
 	"mime"
 	"net/http"
@@ -23,22 +22,35 @@ type Meta struct {
 }
 
 type Store interface {
-	Save(ctx context.Context, id int64, filename string, r io.Reader) (Meta, error)
-	Open(ctx context.Context, id int64) (io.ReadSeekCloser, Meta, error)
-	Stat(ctx context.Context, id int64) (Meta, bool, error)
-	Delete(ctx context.Context, id int64) error
+	Save(ctx context.Context, id string, filename string, r io.Reader) (Meta, error)
+	Open(ctx context.Context, id string) (io.ReadSeekCloser, Meta, error)
+	Stat(ctx context.Context, id string) (Meta, bool, error)
+	Delete(ctx context.Context, id string) error
 }
 
 type FS struct{ root string }
 
 func New(root string) *FS { return &FS{root: root} }
 
-func (fs *FS) dir(id int64) string      { return filepath.Join(fs.root, "files", fmt.Sprintf("%d", id)) }
-func (fs *FS) metaPath(id int64) string { return filepath.Join(fs.dir(id), "meta.json") }
-func (fs *FS) blobPath(id int64, name string) string {
+func (fs *FS) dir(id string) string      { return filepath.Join(fs.root, "files", sanitizeID(id)) }
+func (fs *FS) metaPath(id string) string { return filepath.Join(fs.dir(id), "meta.json") }
+func (fs *FS) blobPath(id string, name string) string {
 	return filepath.Join(fs.dir(id), "blob"+safeExt(name))
 }
 
+func sanitizeID(id string) string {
+	// nur 0-9a-zA-Z- zulassen; Rest mit '_' ersetzen
+	b := make([]rune, 0, len(id))
+	for _, r := range id {
+		if (r >= '0' && r <= '9') || (r >= 'a' && r <= 'z') || (r >= 'A' && r <= 'Z') || r == '-' {
+			b = append(b, r)
+		} else {
+			b = append(b, '_')
+		}
+	}
+	return string(b)
+}
+
 func safeExt(name string) string {
 	ext := filepath.Ext(name)
 	if len(ext) > 16 { // unrealistisch lange Exts beschneiden
@@ -47,7 +59,7 @@ func safeExt(name string) string {
 	return ext
 }
 
-func (fs *FS) Save(_ context.Context, id int64, filename string, r io.Reader) (Meta, error) {
+func (fs *FS) Save(_ context.Context, id string, filename string, r io.Reader) (Meta, error) {
 	if strings.TrimSpace(filename) == "" {
 		return Meta{}, errors.New("filename required")
 	}
@@ -107,7 +119,7 @@ func (fs *FS) Save(_ context.Context, id int64, filename string, r io.Reader) (M
 	return meta, nil
 }
 
-func (fs *FS) Open(_ context.Context, id int64) (io.ReadSeekCloser, Meta, error) {
+func (fs *FS) Open(_ context.Context, id string) (io.ReadSeekCloser, Meta, error) {
 	meta, ok, err := fs.Stat(context.Background(), id)
 	if err != nil {
 		return nil, Meta{}, err
@@ -119,7 +131,7 @@ func (fs *FS) Open(_ context.Context, id int64) (io.ReadSeekCloser, Meta, error)
 	return f, meta, err
 }
 
-func (fs *FS) Stat(_ context.Context, id int64) (Meta, bool, error) {
+func (fs *FS) Stat(_ context.Context, id string) (Meta, bool, error) {
 	b, err := os.ReadFile(fs.metaPath(id))
 	if err != nil {
 		if os.IsNotExist(err) {
@@ -139,7 +151,7 @@ func (fs *FS) Stat(_ context.Context, id int64) (Meta, bool, error) {
 	return m, true, nil
 }
 
-func (fs *FS) Delete(_ context.Context, id int64) error {
+func (fs *FS) Delete(_ context.Context, id string) error {
 	return os.RemoveAll(fs.dir(id))
 }
 

internal/filesvc/memstore.go

@@ -2,6 +2,9 @@ package filesvc
 
 import (
 	"context"
+	"encoding/json"
+	"os"
+	"path/filepath"
 	"slices"
 	"strings"
 	"sync"
@@ -11,17 +14,82 @@ import (
 type MemStore struct {
 	mu    sync.Mutex
 	items map[ID]File
-	next  ID
-
+	self  string
 	// optionales Eventing
-	subs []chan ChangeEvent
+	subs        []chan ChangeEvent
+	persistPath string
 }
 
-func NewMemStore() *MemStore {
-	return &MemStore{
-		items: make(map[ID]File),
-		next:  1,
+func NewMemStore(self string) *MemStore {
+	return &MemStore{self: strings.TrimSpace(self), items: make(map[ID]File)}
+}
+
+func NewMemStorePersistent(self, path string) *MemStore {
+	m := NewMemStore(self)
+	m.persistPath = strings.TrimSpace(path)
+	// beim Start versuchen zu laden
+	_ = m.loadFromDisk()
+	return m
+}
+
+// --- Persistenz-Helper (NEU) ---
+
+func (m *MemStore) loadFromDisk() error {
+	if m.persistPath == "" {
+		return nil
 	}
+	f, err := os.Open(m.persistPath)
+	if err != nil {
+		return nil // Datei existiert beim ersten Start nicht – ok
+	}
+	defer f.Close()
+	var snap Snapshot
+	if err := json.NewDecoder(f).Decode(&snap); err != nil {
+		return err
+	}
+	m.mu.Lock()
+	for _, it := range snap.Items {
+		m.items[it.ID] = it
+	}
+	m.mu.Unlock()
+	return nil
+}
+
+func (m *MemStore) saveLocked() error {
+	if m.persistPath == "" {
+		return nil
+	}
+	if err := os.MkdirAll(filepath.Dir(m.persistPath), 0o755); err != nil {
+		return err
+	}
+	// Snapshot aus Map bauen
+	snap := Snapshot{Items: make([]File, 0, len(m.items))}
+	for _, it := range m.items {
+		snap.Items = append(snap.Items, it)
+	}
+	// atomar schreiben
+	tmp := m.persistPath + ".tmp"
+	f, err := os.Create(tmp)
+	if err != nil {
+		return err
+	}
+	enc := json.NewEncoder(f)
+	enc.SetIndent("", "  ")
+	if err := enc.Encode(&snap); err != nil {
+		f.Close()
+		_ = os.Remove(tmp)
+		return err
+	}
+	if err := f.Sync(); err != nil {
+		f.Close()
+		_ = os.Remove(tmp)
+		return err
+	}
+	if err := f.Close(); err != nil {
+		_ = os.Remove(tmp)
+		return err
+	}
+	return os.Rename(tmp, m.persistPath)
 }
 
 /*** Store ***/
@@ -39,39 +107,54 @@ func (m *MemStore) Get(_ context.Context, id ID) (File, error) {
 func (m *MemStore) List(_ context.Context, next ID, limit int) ([]File, ID, error) {
 	m.mu.Lock()
 	defer m.mu.Unlock()
+
 	if limit <= 0 || limit > 1000 {
 		limit = 100
 	}
-	ids := make([]ID, 0, len(m.items))
-	for id := range m.items {
-		ids = append(ids, id)
+
+	// sortiere deterministisch nach UpdatedAt, dann ID
+	all := make([]File, 0, len(m.items))
+	for _, v := range m.items {
+		all = append(all, v)
 	}
-	slices.Sort(ids)
+	slices.SortFunc(all, func(a, b File) int {
+		if a.UpdatedAt == b.UpdatedAt {
+			if a.ID == b.ID {
+				return 0
+			}
+			if a.ID < b.ID {
+				return -1
+			}
+			return 1
+		}
+		if a.UpdatedAt < b.UpdatedAt {
+			return -1
+		}
+		return 1
+	})
 
 	start := 0
-	if next > 0 {
-		for i, id := range ids {
-			if id >= next {
+	if next != "" {
+		for i, it := range all {
+			if it.ID >= next {
 				start = i
 				break
 			}
 		}
 	}
 	end := start + limit
-	if end > len(ids) {
-		end = len(ids)
+	if end > len(all) {
+		end = len(all)
 	}
-
 	out := make([]File, 0, end-start)
-	for _, id := range ids[start:end] {
-		it := m.items[id]
+	for _, it := range all[start:end] {
 		if !it.Deleted {
 			out = append(out, it)
 		}
 	}
 	var nextOut ID
-	if end < len(ids) {
-		nextOut = ids[end]
+	if end < len(all) {
+		nextOut = all[end].ID
 	}
 	return out, nextOut, nil
 }
@@ -85,9 +168,13 @@ func (m *MemStore) Create(_ context.Context, name string) (File, error) {
 	m.mu.Lock()
 	defer m.mu.Unlock()
 	now := time.Now().UnixNano()
-	it := File{ID: m.next, Name: name, UpdatedAt: now}
+	uid, err := NewUUIDv4()
+	if err != nil {
+		return File{}, err
+	}
+	it := File{ID: uid, Name: name, UpdatedAt: now, Owner: m.self}
 	m.items[it.ID] = it
-	m.next++
+	_ = m.saveLocked()
 	m.emit(it)
 	return it, nil
 }
@@ -104,9 +191,13 @@ func (m *MemStore) Rename(_ context.Context, id ID, newName string) (File, error
 	if !ok || it.Deleted {
 		return File{}, ErrNotFound
 	}
-	it.Name = newName
+	if it.Owner != "" && it.Owner != m.self { // ← nur Owner
+		return File{}, ErrForbidden
+	}
+	it.Name = strings.TrimSpace(newName)
 	it.UpdatedAt = time.Now().UnixNano()
 	m.items[id] = it
+	_ = m.saveLocked()
 	m.emit(it)
 	return it, nil
 }
@@ -118,16 +209,46 @@ func (m *MemStore) Delete(_ context.Context, id ID) (File, error) {
 	if !ok {
 		return File{}, ErrNotFound
 	}
+	if it.Owner != "" && it.Owner != m.self { // ← nur Owner
+		return File{}, ErrForbidden
+	}
 	if it.Deleted {
 		return it, nil
 	}
 	it.Deleted = true
 	it.UpdatedAt = time.Now().UnixNano()
 	m.items[id] = it
+	_ = m.saveLocked()
 	m.emit(it)
 	return it, nil
 }
 
+func (m *MemStore) TakeoverOwner(_ context.Context, id ID, newOwner string) (File, error) {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+	it, ok := m.items[id]
+	if !ok || it.Deleted {
+		return File{}, ErrNotFound
+	}
+	newOwner = strings.TrimSpace(newOwner)
+	if newOwner == "" {
+		return File{}, ErrBadInput
+	}
+	// Sicherheit: nur für sich selbst übernehmen
+	if newOwner != m.self {
+		return File{}, ErrForbidden
+	}
+	if it.Owner == newOwner {
+		return it, nil
+	}
+	it.Owner = newOwner
+	it.UpdatedAt = time.Now().UnixNano()
+	m.items[id] = it
+	_ = m.saveLocked()
+	m.emitLocked(it)
+	return it, nil
+}
+
 /*** Replicable ***/
 
 func (m *MemStore) Snapshot(_ context.Context) (Snapshot, error) {
@@ -143,16 +264,22 @@ func (m *MemStore) Snapshot(_ context.Context) (Snapshot, error) {
 func (m *MemStore) ApplyRemote(_ context.Context, s Snapshot) error {
 	m.mu.Lock()
 	defer m.mu.Unlock()
+	changed := false
 	for _, ri := range s.Items {
 		li, ok := m.items[ri.ID]
 		if !ok || ri.UpdatedAt > li.UpdatedAt {
-			m.items[ri.ID] = ri
-			if ri.ID >= m.next {
-				m.next = ri.ID + 1
+			// Owner nie überschreiben, außer er ist leer
+			if ok && li.Owner != "" && ri.Owner != "" && ri.Owner != li.Owner {
+				ri.Owner = li.Owner
 			}
+			m.items[ri.ID] = ri
+			changed = true
 			m.emitLocked(ri)
 		}
 	}
+	if changed {
+		_ = m.saveLocked() // ← NEU
+	}
 	return nil
 }
 

internal/filesvc/store.go

@@ -2,20 +2,22 @@ package filesvc
 
 import (
 	"context"
+	"crypto/rand"
 	"errors"
+	"fmt"
 	"time"
 )
 
 /*** Domain ***/
 
-type ID = int64
+type ID = string
 
 type File struct {
-	ID   ID     `json:"id"`
-	Name string `json:"name"`
-	// weitere Metadaten optional: Size, Hash, Owner, Tags, ...
-	UpdatedAt int64 `json:"updatedAt"` // UnixNano für LWW
-	Deleted   bool  `json:"deleted"`   // Tombstone für Mesh-Delete
+	ID        ID     `json:"id"`
+	Name      string `json:"name"`
+	UpdatedAt int64  `json:"updatedAt"` // UnixNano für LWW
+	Deleted   bool   `json:"deleted"`   // Tombstone für Mesh-Delete
+	Owner     string `json:"owner"`     //AdvertURL/NodeID des Erzeugers
 }
 
 /*** Fehler ***/
@@ -34,11 +36,10 @@ type Store interface {
 	// Lesen & Auflisten
 	Get(ctx context.Context, id ID) (File, error)
 	List(ctx context.Context, next ID, limit int) (items []File, nextOut ID, err error)
-
-	// Mutationen mit LWW-Semantik (UpdatedAt wird intern gesetzt, außer bei ApplyRemote)
 	Create(ctx context.Context, name string) (File, error)
-	Rename(ctx context.Context, id ID, newName string) (File, error)
-	Delete(ctx context.Context, id ID) (File, error)
+	Rename(ctx context.Context, id ID, newName string) (File, error) // nur Owner darf
+	Delete(ctx context.Context, id ID) (File, error)                 // nur Owner darf
+	TakeoverOwner(ctx context.Context, id ID, newOwner string) (File, error)
 }
 
 /*** Mesh-Replikation ***/
@@ -76,3 +77,13 @@ type MeshStore interface {
 	Replicable
 	Watchable // optional – kann Noop sein
 }
+
+func NewUUIDv4() (string, error) {
+	b := make([]byte, 16)
+	if _, err := rand.Read(b); err != nil {
+		return "", err
+	}
+	b[6] = (b[6] & 0x0f) | 0x40 // Version 4
+	b[8] = (b[8] & 0x3f) | 0x80 // Variant RFC4122
+	return fmt.Sprintf("%x-%x-%x-%x-%x", b[0:4], b[4:6], b[6:8], b[8:10], b[10:16]), nil
+}

internal/mesh/mesh.go

@@ -8,13 +8,16 @@ import (
 	"encoding/hex"
 	"encoding/json"
 	"errors"
+	"fmt"
 	"hash/crc32"
 	"io"
 	"log"
+	"math/rand/v2"
 	"net"
 	"net/http"
 	"os"
 	"slices"
+	"strconv"
 	"strings"
 	"sync"
 	"time"
@@ -28,7 +31,18 @@ type Config struct {
 	Seeds            []string // other peers' mesh base URLs
 	ClusterSecret    string   // HMAC key
 	EnableDiscovery  bool
-	DiscoveryAddress string // "239.8.8.8:9898"
+	DiscoveryAddress string        // "239.8.8.8:9898"
+	PeerTTL          time.Duration // wie lange darf ein Peer inaktiv sein (Default siehe unten)
+	PruneInterval    time.Duration // wie oft wird gepruned
+
+	SyncInterval time.Duration
+	Fanout       int
+
+	// NEU:
+	HelloInterval time.Duration // wie oft pingen
+	HelloFanout   int           // wie viele Peers pro Tick
+
+	BlobTimeout time.Duration
 }
 
 type Peer struct {
@@ -39,10 +53,11 @@ type Peer struct {
 }
 
 type Item struct {
-	ID        int64  `json:"id"`
+	ID        string `json:"id"`
 	Name      string `json:"name"`
 	UpdatedAt int64  `json:"updatedAt"`
 	Deleted   bool   `json:"deleted"` // <— NEU: Tombstone für Deletes
+	Owner     string `json:"owner"`
 }
 
 type Snapshot struct {
@@ -53,6 +68,7 @@ type Snapshot struct {
 type Callbacks struct {
 	GetSnapshot func(ctx context.Context) (Snapshot, error)
 	ApplyRemote func(ctx context.Context, s Snapshot) error
+	BlobOpen    func(ctx context.Context, id string) (io.ReadCloser, string, string, int64, error)
 }
 
 /*** Node ***/
@@ -69,6 +85,80 @@ type Node struct {
 	wg     sync.WaitGroup
 }
 
+// RemovePeer löscht einen Peer aus der Peer-Tabelle. Seeds werden standardmäßig nicht entfernt.
+func (n *Node) RemovePeer(url string) bool {
+	n.mu.Lock()
+	defer n.mu.Unlock()
+	if url == "" || url == n.self.URL {
+		return false
+	}
+	// Seeds schützen
+	if n.isSeed(url) {
+		return false
+	}
+	if _, ok := n.peers[url]; ok {
+		delete(n.peers, url)
+		return true
+	}
+	return false
+}
+
+func (n *Node) Config() Config { return n.cfg }
+
+// PruneNow entfernt alle Peers, deren LastSeen vor cutoff liegt (Seeds bleiben).
+func (n *Node) PruneNow(cutoff time.Time) int {
+	n.mu.Lock()
+	defer n.mu.Unlock()
+	removed := 0
+	for url, p := range n.peers {
+		if url == n.self.URL || n.isSeed(url) {
+			continue
+		}
+		if p.LastSeen.IsZero() || p.LastSeen.Before(cutoff) {
+			delete(n.peers, url)
+			removed++
+		}
+	}
+	return removed
+}
+
+// StartPeerPruner startet den Hintergrundjob (stoppt automatisch bei n.stop).
+func (n *Node) StartPeerPruner() {
+	go n.loopPrunePeers()
+}
+
+func (n *Node) loopPrunePeers() {
+	ttl := n.cfg.PeerTTL
+	if ttl <= 0 {
+		ttl = 2 * time.Minute
+	}
+	interval := n.cfg.PruneInterval
+	if interval <= 0 {
+		interval = 30 * time.Second
+	}
+	t := time.NewTicker(interval)
+	defer t.Stop()
+	for {
+		select {
+		case <-n.stop:
+			return
+		case <-t.C:
+			cutoff := time.Now().Add(-ttl)
+			_ = n.PruneNow(cutoff)
+		}
+	}
+}
+
+// helper: ist url ein Seed?
+func (n *Node) isSeed(url string) bool {
+	for _, s := range n.cfg.Seeds {
+		if strings.TrimSpace(s) == strings.TrimSpace(url) {
+			return true
+		}
+	}
+	return false
+}
+
 func New(cfg Config, cbs Callbacks) (*Node, error) {
 	if cfg.BindAddr == "" || cfg.AdvertURL == "" {
 		return nil, errors.New("mesh: BindAddr and AdvertURL required")
@@ -110,21 +200,38 @@ func (n *Node) helloHandler(w http.ResponseWriter, r *http.Request) {
 		http.Error(w, "bad signature", http.StatusUnauthorized)
 		return
 	}
-	var p Peer
-	if err := json.Unmarshal(body, &p); err != nil {
+	var req struct {
+		URL string `json:"url"`
+	}
+	if err := json.Unmarshal(body, &req); err != nil || strings.TrimSpace(req.URL) == "" {
 		http.Error(w, "bad json", http.StatusBadRequest)
 		return
 	}
-	p.LastSeen = time.Now()
+
+	// Peer anlegen (falls neu) und LastSeen setzen
 	n.mu.Lock()
-	if existing, ok := n.peers[p.URL]; ok {
-		existing.LastSeen = p.LastSeen
-	} else if p.URL != n.self.URL {
-		cp := p
-		n.peers[p.URL] = &cp
+	if req.URL != n.self.URL {
+		if p, ok := n.peers[req.URL]; ok {
+			p.LastSeen = time.Now()
+		} else {
+			cp := Peer{URL: req.URL, LastSeen: time.Now()} // weitere Felder wie bekannt
+			n.peers[req.URL] = &cp
+		}
+	}
+	n.mu.Unlock()
+
+	w.WriteHeader(http.StatusOK)
+}
+
+func (n *Node) touchPeer(url string) {
+	if strings.TrimSpace(url) == "" {
+		return
+	}
+	n.mu.Lock()
+	if p, ok := n.peers[url]; ok {
+		p.LastSeen = time.Now()
 	}
 	n.mu.Unlock()
-	w.WriteHeader(http.StatusNoContent)
 }
 
 func (n *Node) peersHandler(w http.ResponseWriter, r *http.Request) {
@@ -133,6 +240,7 @@ func (n *Node) peersHandler(w http.ResponseWriter, r *http.Request) {
 	var list []Peer
 	list = append(list, n.self)
 	for _, p := range n.peers {
+		//p.Self = false
 		list = append(list, *p)
 	}
 	writeJSON(w, http.StatusOK, list)
@@ -170,6 +278,7 @@ func (n *Node) Serve() error {
 	mux := http.NewServeMux()
 	mux.HandleFunc("/mesh/peers", n.peersHandler)
 	mux.HandleFunc("/mesh/hello", n.helloHandler)
+	mux.HandleFunc("/mesh/blob", n.blobHandler)
 	mux.HandleFunc("/mesh/sync", n.syncHandler)
 	n.srv = &http.Server{Addr: n.cfg.BindAddr, Handler: mux}
 
@@ -180,6 +289,9 @@ func (n *Node) Serve() error {
 		n.loopSeeder()
 	}()
 
+	n.wg.Add(1)
+	go func() { defer n.wg.Done(); n.loopPeerExchange() }()
+
 	if n.cfg.EnableDiscovery && n.cfg.DiscoveryAddress != "" {
 		n.wg.Add(2)
 		go func() {
@@ -198,6 +310,12 @@ func (n *Node) Serve() error {
 		n.loopAntiEntropy()
 	}()
 
+	n.wg.Add(1)
+	go func() {
+		defer n.wg.Done()
+		n.loopHello()
+	}()
+
 	// http server
 	errc := make(chan error, 1)
 	go func() {
@@ -222,6 +340,43 @@ func (n *Node) Close(ctx context.Context) error {
 
 /*** Loops ***/
 
+func (n *Node) loopPeerExchange() {
+	t := time.NewTicker(30 * time.Second)
+	defer t.Stop()
+	for {
+		select {
+		case <-n.stop:
+			return
+		case <-t.C:
+		}
+		// Seeds abfragen
+		for _, s := range n.cfg.Seeds {
+			if strings.TrimSpace(s) == "" {
+				continue
+			}
+			resp, err := n.client.Get(strings.TrimRight(s, "/") + "/mesh/peers")
+			if err != nil {
+				continue
+			}
+			var list []Peer
+			if json.NewDecoder(resp.Body).Decode(&list) == nil {
+				n.mu.Lock()
+				for _, p := range list {
+					if p.URL == "" || p.URL == n.self.URL {
+						continue
+					}
+					if _, ok := n.peers[p.URL]; !ok {
+						cp := p
+						n.peers[p.URL] = &cp
+					}
+				}
+				n.mu.Unlock()
+			}
+			resp.Body.Close()
+		}
+	}
+}
+
 func (n *Node) loopSeeder() {
 	// attempt to hello known seeds every 5s at start, then every 30s
 	backoff := 5 * time.Second
@@ -345,28 +500,100 @@ func (n *Node) loopBeaconRecv() {
 /*** Outgoing ***/
 
 func (n *Node) sendHello(url string) error {
-	p := n.self
-	b, _ := json.Marshal(p)
+	b, _ := json.Marshal(struct {
+		URL string `json:"url"`
+	}{URL: n.self.URL})
 	req, _ := http.NewRequest(http.MethodPost, strings.TrimRight(url, "/")+"/mesh/hello", bytes.NewReader(b))
 	req.Header.Set("X-Mesh-Sig", n.sign(b))
+
 	resp, err := n.client.Do(req)
-	if err == nil {
-		io.Copy(io.Discard, resp.Body)
-		resp.Body.Close()
+	if err != nil {
+		return err
+	}
+	io.Copy(io.Discard, resp.Body)
+	resp.Body.Close()
+	if resp.StatusCode == http.StatusOK {
+		n.touchPeer(url) // eigenen Blick auf den Peer direkt als „gesehen“ markieren
+		return nil
+	}
+	return fmt.Errorf("hello %s: %s", url, resp.Status)
+}
+
+func (n *Node) loopHello() {
+	interval := n.cfg.HelloInterval
+	if interval <= 0 {
+		interval = 20 * time.Second
+	}
+	fanout := n.cfg.HelloFanout
+	if fanout <= 0 {
+		fanout = 8
+	}
+
+	t := time.NewTicker(interval)
+	defer t.Stop()
+
+	for {
+		select {
+		case <-n.stop:
+			return
+		case <-t.C:
+		}
+
+		// Liste der *bekannten* Peers (nicht nur Seeds)
+		n.mu.RLock()
+		targets := make([]string, 0, len(n.peers))
+		for url := range n.peers {
+			if url != n.self.URL {
+				targets = append(targets, url)
+			}
+		}
+		n.mu.RUnlock()
+		if len(targets) == 0 {
+			continue
+		}
+
+		// zufällig mischen und auf Fanout begrenzen
+		rand.Shuffle(len(targets), func(i, j int) { targets[i], targets[j] = targets[j], targets[i] })
+		if fanout < len(targets) {
+			targets = targets[:fanout]
+		}
+
+		// leicht parallel pingen
+		var wg sync.WaitGroup
+		for _, u := range targets {
+			u := u
+			wg.Add(1)
+			go func() {
+				defer wg.Done()
+				_ = n.sendHello(u)
+			}()
+		}
+		wg.Wait()
 	}
-	return err
 }
 
 func (n *Node) sendSync(url string, s Snapshot) error {
 	b, _ := json.Marshal(s)
 	req, _ := http.NewRequest(http.MethodPost, strings.TrimRight(url, "/")+"/mesh/sync", bytes.NewReader(b))
 	req.Header.Set("X-Mesh-Sig", n.sign(b))
+
+	ctx, cancel := context.WithTimeout(context.Background(), 4*time.Second)
+	defer cancel()
+	req = req.WithContext(ctx)
+
 	resp, err := n.client.Do(req)
-	if err == nil {
-		io.Copy(io.Discard, resp.Body)
-		resp.Body.Close()
+	if err != nil {
+		return err
 	}
-	return err
+	defer resp.Body.Close()
+	io.Copy(io.Discard, resp.Body)
+
+	if resp.StatusCode != http.StatusOK {
+		return fmt.Errorf("sync %s: %s", url, resp.Status)
+	}
+
+	n.touchPeer(url)
+	return nil
 }
 
 // PeerList liefert eine Kopie der bekannten Peers inkl. Self.
@@ -377,6 +604,7 @@ func (n *Node) PeerList() []Peer {
 	out = append(out, n.self)
 	for _, p := range n.peers {
 		cp := *p
+		cp.Self = false
 		out = append(out, cp)
 	}
 	return out
@@ -403,11 +631,11 @@ func (n *Node) SyncNow(ctx context.Context) error {
 /*** Utilities ***/
 
 // OwnerHint is a simple, optional mapping to distribute responsibility.
-func OwnerHint(id int64, peers []string) int {
+func OwnerHint(id string, peers []string) int {
 	if len(peers) == 0 {
 		return 0
 	}
-	h := crc32.ChecksumIEEE([]byte(string(rune(id))))
+	h := crc32.ChecksumIEEE([]byte(id))
 	return int(h % uint32(len(peers)))
 }
 
@@ -449,3 +677,109 @@ func getenvDefault(k, def string) string {
 	}
 	return v
 }
+
+// POST /mesh/blob  (Body: {"id":<int64>}) -> streamt den Blob
+func (n *Node) blobHandler(w http.ResponseWriter, r *http.Request) {
+	body, _ := io.ReadAll(r.Body)
+	if !n.verify(body, r.Header.Get("X-Mesh-Sig")) {
+		http.Error(w, "bad signature", http.StatusUnauthorized)
+		return
+	}
+	var req struct {
+		ID string `json:"id"`
+	}
+	if err := json.Unmarshal(body, &req); err != nil {
+		http.Error(w, "bad json", http.StatusBadRequest)
+		return
+	}
+	if n.cbs.BlobOpen == nil {
+		http.Error(w, "blob unavailable", http.StatusNotFound)
+		return
+	}
+	rc, name, ct, size, err := n.cbs.BlobOpen(r.Context(), req.ID)
+	if err != nil {
+		http.Error(w, "not found", http.StatusNotFound)
+		return
+	}
+	defer rc.Close()
+	if ct == "" {
+		ct = "application/octet-stream"
+	}
+	if size > 0 {
+		w.Header().Set("Content-Length", strconv.FormatInt(size, 10))
+	}
+	w.Header().Set("Content-Type", ct)
+	w.Header().Set("X-Blob-Name", name)
+	_, _ = io.Copy(w, rc)
+}
+
+// sendBlobRequest schickt eine signierte Anfrage an /mesh/blob und liefert die Response
+// zurück (Caller MUSS resp.Body schließen!). Bei HTTP 200 wird der Peer als gesehen markiert.
+func (n *Node) sendBlobRequest(url, id string) (*http.Response, error) {
+	b, _ := json.Marshal(struct {
+		ID string `json:"id"`
+	}{ID: id})
+
+	req, _ := http.NewRequest(http.MethodPost, strings.TrimRight(url, "/")+"/mesh/blob", bytes.NewReader(b))
+	req.Header.Set("X-Mesh-Sig", n.sign(b))
+	req.Header.Set("Content-Type", "application/json")
+
+	// ❗ WICHTIG: kein kurzer Timeout. Optional: großer Timeout aus Config
+	ctx := context.Background()
+	if n.cfg.BlobTimeout > 0 {
+		var cancel context.CancelFunc
+		ctx, cancel = context.WithTimeout(context.Background(), n.cfg.BlobTimeout)
+		defer cancel()
+	}
+	req = req.WithContext(ctx)
+
+	resp, err := n.client.Do(req)
+	if err != nil {
+		return nil, err
+	}
+	if resp.StatusCode == http.StatusOK {
+		n.touchPeer(url) // ausgehender Erfolg zählt als "gesehen"
+		return resp, nil
+	}
+	io.Copy(io.Discard, resp.Body)
+	resp.Body.Close()
+	return nil, fmt.Errorf("blob %s from %s: %s", id, url, resp.Status)
+}
+
+// Öffentliche Methode: versuche Blob bei irgendeinem Peer zu holen
+func (n *Node) FetchBlobAny(ctx context.Context, id string) (io.ReadCloser, string, string, int64, error) {
+	n.mu.RLock()
+	targets := make([]string, 0, len(n.peers))
+	for url := range n.peers {
+		targets = append(targets, url)
+	}
+	n.mu.RUnlock()
+	if len(targets) == 0 {
+		// Fallback: Seeds probieren
+		targets = append(targets, n.cfg.Seeds...)
+	}
+	for _, u := range targets {
+		if strings.TrimSpace(u) == "" || u == n.self.URL {
+			continue
+		}
+		resp, err := n.sendBlobRequest(u, id)
+		if err != nil {
+			continue
+		}
+		if resp.StatusCode == http.StatusOK {
+			name := resp.Header.Get("X-Blob-Name")
+			ct := resp.Header.Get("Content-Type")
+			var size int64 = -1
+			if cl := resp.Header.Get("Content-Length"); cl != "" {
+				if s, err := strconv.ParseInt(cl, 10, 64); err == nil {
+					size = s
+				}
+			}
+			// Caller muss resp.Body schließen
+			return resp.Body, name, ct, size, nil
+		}
+		io.Copy(io.Discard, resp.Body)
+		resp.Body.Close()
+	}
+	return nil, "", "", 0, fmt.Errorf("blob %s not found on peers", id)
+}