feat: Retry-Funktion + idempotente Pipeline (Transkript bleibt erhalten)

Backend:
- POST /api/jobs/{id}/retry — löscht summary/protocol/docx, queued den Job
  neu und startet Pipeline. Transkript bleibt erhalten (teurer Schritt).
- Pipeline überspringt Steps, deren Output-Datei schon existiert →
  retry rennt direkt in summarize ohne erneute Transkription.

Frontend:
- Kleiner gelber '↻ Erneut versuchen'-Button in jeder Job-Zeile/-Karte
  wenn Status != done
- Confirm-Dialog erklärt was passiert
- Event-Delegation, funktioniert für Tabelle (Desktop) und Cards (Mobile)

lxc-frontend/app/api/jobs.py

@@ -90,6 +90,44 @@ def get_job(job_id: int, session: Session = Depends(get_session), user: User = D
     return _job_dict(job, user)
 
 
+@router.post("/{job_id}/retry")
+async def retry_job(
+    job_id: int,
+    background: BackgroundTasks,
+    session: Session = Depends(get_session),
+    user: User = Depends(current_user),
+):
+    """Verarbeitung neu anstoßen.
+
+    Bereits vorhandenes Transkript wird beibehalten (teuerster Schritt),
+    Summary/Protokoll/DOCX werden gelöscht und neu erzeugt. Sinnvoll wenn
+    der Job bei summarize/protocol/docx hängt oder failed ist.
+    """
+    job = _require_access(session.get(Job, job_id), user)
+    if job.status == JobStatus.DONE:
+        raise HTTPException(400, "Job ist bereits abgeschlossen")
+
+    # Post-Transkriptions-Artefakte löschen, damit sie neu erzeugt werden.
+    for attr in ("summary_path", "protocol_path", "docx_path"):
+        p = getattr(job, attr)
+        if p:
+            try:
+                Path(p).unlink(missing_ok=True)
+            except OSError:
+                pass
+        setattr(job, attr, "")
+
+    job.status = JobStatus.QUEUED
+    job.progress = 0
+    job.error = ""
+    session.add(job)
+    session.commit()
+    session.refresh(job)
+
+    background.add_task(run_pipeline, job.id)
+    return _job_dict(job, user)
+
+
 @router.get("/{job_id}/download/{kind}")
 def download(job_id: int, kind: str, session: Session = Depends(get_session), user: User = Depends(current_user)):
     job = _require_access(session.get(Job, job_id), user)

lxc-frontend/app/services/pipeline.py

@@ -25,8 +25,19 @@ def _update(job_id: int, **fields) -> None:
         s.commit()
 
 
+def _existing(path_str: str) -> Path | None:
+    if not path_str:
+        return None
+    p = Path(path_str)
+    return p if p.exists() and p.stat().st_size > 0 else None
+
+
 async def run_pipeline(job_id: int) -> None:
-    """Run the full pipeline: transcribe → summarize → protocol → DOCX."""
+    """Pipeline: transcribe → summarize → protocol → DOCX.
+
+    Idempotent: bereits vorhandene Zwischenergebnisse werden weiterverwendet,
+    damit ein 'Erneut versuchen' nicht die teure Transkription wiederholt.
+    """
     client = MacClient()
 
     with Session(engine) as s:
@@ -37,40 +48,69 @@ async def run_pipeline(job_id: int) -> None:
         audio_path = settings.upload_dir / job.filename
         title = job.title or audio_path.stem
         profile = job.profile or "meeting"
+        existing_tx_path  = _existing(job.transcript_path)
+        existing_sum_path = _existing(job.summary_path)
+        existing_pro_path = _existing(job.protocol_path)
+        existing_dx_path  = _existing(job.docx_path)
 
     job_dir = settings.result_dir / str(job_id)
     job_dir.mkdir(parents=True, exist_ok=True)
 
     try:
-        _update(job_id, status=JobStatus.TRANSCRIBING, progress=10)
+        # 1) TRANSKRIPTION
-        log.info("[job %s] transcribe (profile=%s)", job_id, profile)
+        if existing_tx_path:
-        tx = await client.transcribe(audio_path, language="de")
+            log.info("[job %s] reuse transcript %s", job_id, existing_tx_path.name)
-        transcript_path = job_dir / "transcript.json"
+            tx = json.loads(existing_tx_path.read_text(encoding="utf-8"))
-        transcript_path.write_text(json.dumps(tx, ensure_ascii=False, indent=2), encoding="utf-8")
+            _update(job_id, status=JobStatus.TRANSCRIBING, progress=45)
-        _update(job_id, transcript_path=str(transcript_path), progress=45)
+        else:
+            _update(job_id, status=JobStatus.TRANSCRIBING, progress=10, error="")
+            log.info("[job %s] transcribe (profile=%s)", job_id, profile)
+            tx = await client.transcribe(audio_path, language="de")
+            transcript_path = job_dir / "transcript.json"
+            transcript_path.write_text(json.dumps(tx, ensure_ascii=False, indent=2), encoding="utf-8")
+            _update(job_id, transcript_path=str(transcript_path), progress=45)
 
-        transcript_text = tx.get("text") or "\n".join(s.get("text", "") for s in tx.get("segments", []))
+        transcript_text = tx.get("text") or "\n".join(
+            s.get("text", "") for s in tx.get("segments", [])
+        )
 
-        _update(job_id, status=JobStatus.SUMMARIZING, progress=55)
+        # 2) SUMMARY
-        log.info("[job %s] summarize", job_id)
+        if existing_sum_path:
-        summary = await client.summarize(transcript_text, title=title, profile=profile)
+            log.info("[job %s] reuse summary %s", job_id, existing_sum_path.name)
-        summary_path = job_dir / "summary.json"
+            summary = json.loads(existing_sum_path.read_text(encoding="utf-8"))
-        summary_path.write_text(json.dumps(summary, ensure_ascii=False, indent=2), encoding="utf-8")
+            _update(job_id, status=JobStatus.SUMMARIZING, progress=70)
-        _update(job_id, summary_path=str(summary_path), progress=70)
+        else:
+            _update(job_id, status=JobStatus.SUMMARIZING, progress=55)
+            log.info("[job %s] summarize", job_id)
+            summary = await client.summarize(transcript_text, title=title, profile=profile)
+            summary_path = job_dir / "summary.json"
+            summary_path.write_text(json.dumps(summary, ensure_ascii=False, indent=2), encoding="utf-8")
+            _update(job_id, summary_path=str(summary_path), progress=70)
 
-        _update(job_id, status=JobStatus.PROTOCOLLING, progress=75)
+        # 3) PROTOKOLL
-        log.info("[job %s] protocol", job_id)
+        if existing_pro_path:
-        protocol = await client.protocol(transcript_text, summary, title=title, profile=profile)
+            log.info("[job %s] reuse protocol %s", job_id, existing_pro_path.name)
-        protocol_path = job_dir / "protocol.json"
+            protocol = json.loads(existing_pro_path.read_text(encoding="utf-8"))
-        protocol_path.write_text(json.dumps(protocol, ensure_ascii=False, indent=2), encoding="utf-8")
+            _update(job_id, status=JobStatus.PROTOCOLLING, progress=85)
-        _update(job_id, protocol_path=str(protocol_path), progress=85)
+        else:
+            _update(job_id, status=JobStatus.PROTOCOLLING, progress=75)
+            log.info("[job %s] protocol", job_id)
+            protocol = await client.protocol(transcript_text, summary, title=title, profile=profile)
+            protocol_path = job_dir / "protocol.json"
+            protocol_path.write_text(json.dumps(protocol, ensure_ascii=False, indent=2), encoding="utf-8")
+            _update(job_id, protocol_path=str(protocol_path), progress=85)
 
-        _update(job_id, status=JobStatus.EXPORTING, progress=90)
+        # 4) DOCX
-        log.info("[job %s] export docx", job_id)
+        if existing_dx_path:
-        docx_bytes = await client.export_docx(protocol, profile=profile)
+            log.info("[job %s] reuse docx %s", job_id, existing_dx_path.name)
-        docx_path = job_dir / "protocol.docx"
+            _update(job_id, status=JobStatus.DONE, progress=100, error="")
-        docx_path.write_bytes(docx_bytes)
+        else:
-        _update(job_id, docx_path=str(docx_path), status=JobStatus.DONE, progress=100)
+            _update(job_id, status=JobStatus.EXPORTING, progress=90)
+            log.info("[job %s] export docx", job_id)
+            docx_bytes = await client.export_docx(protocol, profile=profile)
+            docx_path = job_dir / "protocol.docx"
+            docx_path.write_bytes(docx_bytes)
+            _update(job_id, docx_path=str(docx_path), status=JobStatus.DONE, progress=100, error="")
         log.info("[job %s] done", job_id)
     except Exception as e:  # noqa: BLE001
         log.exception("[job %s] failed", job_id)

lxc-frontend/app/static/app.js

@@ -290,9 +290,13 @@ function row(job) {
     ? `<span class="tag-profile" title="Verarbeitungs-Profil">${escapeHtml(profileLabelOf(job.profile || "meeting"))}</span>`
     : "";
 
+  const retryBtn = job.status !== "done"
+    ? `<button type="button" class="btn-link btn-retry" data-id="${job.id}" title="Verarbeitung wiederholen (Transkript bleibt erhalten)">↻ Erneut versuchen</button>`
+    : "";
   const statusCell = `
     <span class="status-pill status-${job.status}">${escapeHtml(job.status)}</span>
     ${job.error ? `<div class="status-error" title="${escapeHtml(job.error)}">${escapeHtml(job.error)}</div>` : ""}
+    ${retryBtn}
   `;
 
   tr.innerHTML = `
@@ -337,6 +341,7 @@ function card(job) {
       <small class="muted">${job.progress}%</small>
     </div>
     ${job.error ? `<div class="jc-error" title="${escapeHtml(job.error)}">${escapeHtml(job.error)}</div>` : ""}
+    ${job.status !== "done" ? `<button type="button" class="btn-link btn-retry" data-id="${job.id}">↻ Erneut versuchen</button>` : ""}
     <div class="jc-sub">aktualisiert: ${escapeHtml(fmtDate(job.updated_at))}</div>
     <div class="jc-dl">${dlButtons}</div>
   `;
@@ -666,6 +671,28 @@ adminToggle.addEventListener("click", () => {
   }
 });
 
+// Retry-Button: funktioniert für Tabelle und Karten gleichzeitig (Event-Delegation)
+document.addEventListener("click", async (ev) => {
+  const btn = ev.target.closest(".btn-retry");
+  if (!btn) return;
+  ev.preventDefault();
+  const id = btn.dataset.id;
+  if (!confirm("Verarbeitung erneut starten?\nDas Transkript bleibt erhalten — nur Zusammenfassung, Protokoll und DOCX werden neu erzeugt.")) return;
+  btn.disabled = true;
+  btn.textContent = "wird gestartet …";
+  try {
+    const r = await api(`/api/jobs/${id}/retry`, { method: "POST" });
+    if (!r.ok) {
+      const d = await r.json().catch(() => ({}));
+      alert(d.detail || "Konnte nicht neu starten.");
+      return;
+    }
+    loadJobs();
+  } catch (e) {
+    alert("Netzwerkfehler beim Neustart.");
+  }
+});
+
 // ─── Init ──────────────────────────────────────────────────────────────────
 bootstrap();
 checkMac();

lxc-frontend/app/static/style.css

@@ -530,6 +530,23 @@ select {
   main { padding-bottom: max(20px, env(safe-area-inset-bottom)); }
 }
 
+/* Retry-Button in der Status-Spalte */
+.btn-retry {
+  display: inline-block;
+  margin-top: 6px;
+  padding: 3px 8px;
+  font-size: 11px;
+  font-weight: 500;
+  background: rgba(241,196,15,.12);
+  color: var(--warn);
+  border: 1px solid rgba(241,196,15,.4);
+  border-radius: 5px;
+  text-decoration: none;
+  cursor: pointer;
+}
+.btn-retry:hover { background: rgba(241,196,15,.22); text-decoration: none; }
+.btn-retry:disabled { opacity: .55; cursor: not-allowed; }
+
 /* Profile-Tag in der Job-Zeile */
 .tag-profile {
   display: inline-block;