#10 URL-Routing fuer Podcast-Tiefenlinks

Backend:
- SPA-Fallback: catch-all-Route liefert index.html, falls keine statische Datei
  matcht (mit Ausnahme von /api/* und /audio/*). Dadurch funktionieren Tiefen-
  Links wie /ldn oder /neu-denken direkt.

Frontend:
- loadApp() liest pathname und laedt den passenden Podcast direkt, falls die ID
  in /api/podcasts vorkommt; sonst klassischer Selector.
- selectPodcast() updated den Pfad per history.pushState, damit Bookmarks und
  Sharing funktionieren.
- popstate-Handler reagiert auf Browser-Back/Forward.
- showPodcastList() setzt den Pfad auf '/'.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

backend/app.py

@@ -703,6 +703,25 @@ def startup():
 if os.path.isdir(AUDIO_DIR):
     app.mount("/audio", StaticFiles(directory=AUDIO_DIR), name="audio")
 
-# Serve webapp as static files (fallback)
-if os.path.isdir(STATIC_DIR):
-    app.mount("/", StaticFiles(directory=STATIC_DIR, html=True), name="static")
+
+# SPA-Routing: erst statische Files versuchen, sonst index.html zurueckliefern.
+# Damit funktionieren Tiefen-Links wie /ldn oder /neu-denken (Issue #10).
+@app.get("/")
+def spa_root():
+    index = Path(STATIC_DIR) / "index.html"
+    if index.is_file():
+        return FileResponse(str(index))
+    raise HTTPException(404)
+
+
+@app.get("/{path:path}")
+def spa_fallback(path: str):
+    if path.startswith("api/") or path.startswith("audio/"):
+        raise HTTPException(404)
+    static_path = Path(STATIC_DIR) / path
+    if static_path.is_file():
+        return FileResponse(str(static_path))
+    index = Path(STATIC_DIR) / "index.html"
+    if index.is_file():
+        return FileResponse(str(index))
+    raise HTTPException(404)

webapp/index.html

@@ -1685,7 +1685,13 @@ async function loadApp() {
     const resp = await fetch(`${API_BASE}/api/podcasts`);
     if (resp.ok) {
       const podcasts = await resp.json();
-      if (podcasts.length === 1) {
+      // URL-Routing: /<podcast-id> oeffnet direkt diesen Podcast
+      const pathPodcast = window.location.pathname.replace(/^\//, '').replace(/\/$/, '').split('/')[0];
+      const fromUrl = pathPodcast && podcasts.find(p => p.id === pathPodcast);
+      if (fromUrl) {
+        ALL_PODCASTS = podcasts;
+        await selectPodcast(fromUrl.id, /*fromUrl*/ true);
+      } else if (podcasts.length === 1) {
         // Single podcast → load directly
         await selectPodcast(podcasts[0].id);
       } else if (podcasts.length > 1) {
@@ -1694,6 +1700,15 @@ async function loadApp() {
       } else {
         throw new Error('No podcasts found');
       }
+      // Browser-Back/Forward
+      window.addEventListener('popstate', async () => {
+        const p = window.location.pathname.replace(/^\//, '').replace(/\/$/, '').split('/')[0];
+        if (!p) {
+          showPodcastSelector(podcasts);
+        } else if (podcasts.find(x => x.id === p) && p !== CURRENT_PODCAST) {
+          await selectPodcast(p, true);
+        }
+      });
       return;
     }
   } catch (e) {
@@ -1712,11 +1727,14 @@ async function loadApp() {
   }
 }
 
-async function selectPodcast(podcastId) {
+async function selectPodcast(podcastId, fromUrl = false) {
   try {
     const resp = await fetch(`${API_BASE}/api/podcasts/${podcastId}`);
     DATA = await resp.json();
     CURRENT_PODCAST = podcastId;
+    if (!fromUrl && window.history && window.location.pathname !== `/${podcastId}`) {
+      window.history.pushState({ podcast: podcastId }, '', `/${podcastId}`);
+    }
     // Reset mindmap area (might have been used for selector)
     const mindmap = document.getElementById('mindmap');
     mindmap.style.overflow = 'hidden';
@@ -1914,6 +1932,9 @@ function showPodcastList() {
   CURRENT_PODCAST = null;
   document.getElementById('svg').innerHTML = '';
   document.getElementById('staffel-filters').innerHTML = '';
+  if (window.history && window.location.pathname !== '/') {
+    window.history.pushState({}, '', '/');
+  }
   showPodcastSelector(ALL_PODCASTS);
 }