feat: add parallel file scanning with dedicated executor and support for scanning all sources simultaneously

Add scan_executor ThreadPoolExecutor with 4 workers for parallel file scanning. Import as_completed from concurrent.futures to process scan results. Replace sequential scan_one() loop with parallel futures submission and result collection using as_completed().

Update /api/rescan endpoint to accept "all" source parameter for scanning both Radarr and Sonarr simultaneously. Fix cache deletion

app.py

@@ -7,7 +7,7 @@ import threading
 import time
 import shutil
 import re
-from concurrent.futures import ThreadPoolExecutor
+from concurrent.futures import ThreadPoolExecutor, as_completed
 from datetime import datetime
 from pathlib import Path
 
@@ -31,6 +31,7 @@ logging.basicConfig(level=os.environ.get("LOG_LEVEL", "INFO").upper(), format="%
 log = logging.getLogger("radarr-language-dashboard")
 app = Flask(__name__)
 executor = ThreadPoolExecutor(max_workers=int(os.environ.get("SCAN_WORKERS", "2")))
+scan_executor = ThreadPoolExecutor(max_workers=int(os.environ.get("SCAN_WORKERS", "4")))
 jobs = {"radarr": {"state": "idle", "total": 0, "done": 0, "error": None}, "sonarr": {"state": "idle", "total": 0, "done": 0, "error": None}}
 job_lock = threading.Lock()
 system_lock = threading.Lock()
@@ -283,8 +284,9 @@ def start_scan(source, force=False):
                 for group in sonarr_groups():
                     paths.extend(r["local_path"] for r in group["episodes"] if r["local_path"] != "—" and r["pending"])
             with job_lock: jobs[source]["total"] = len(paths)
-            for path in paths:
-                scan_one(path)
+            futures = [scan_executor.submit(scan_one, path) for path in paths]
+            for future in as_completed(futures):
+                future.result()
                 with job_lock: jobs[source]["done"] += 1
             with job_lock: jobs[source]["state"] = "done"
         except Exception as exc:
@@ -329,11 +331,17 @@ def index():
 @app.post("/api/rescan")
 def api_rescan():
     source = request.args.get("source", "radarr")
-    if source not in jobs: return jsonify({"ok":False, "error":"Unbekannte Quelle"}), 400
+    if source not in (*jobs.keys(), "all"): return jsonify({"ok":False, "error":"Unbekannte Quelle"}), 400
     con = db()
-    if source == "radarr": con.execute("DELETE FROM media_cache")
-    else: con.execute("DELETE FROM media_cache WHERE path LIKE ?", (LOCAL_SERIES_PATH.rstrip("/") + "/%",))
-    con.commit(); con.close(); start_scan(source, force=True)
+    if source in ("radarr", "all"): con.execute("DELETE FROM media_cache WHERE path NOT LIKE ?", (LOCAL_SERIES_PATH.rstrip("/") + "/%",))
+    if source in ("sonarr", "all"): con.execute("DELETE FROM media_cache WHERE path LIKE ?", (LOCAL_SERIES_PATH.rstrip("/") + "/%",))
+    con.commit(); con.close()
+    if source == "all":
+        start_scan("radarr", force=True)
+        if SONARR_URL and SONARR_API_KEY:
+            start_scan("sonarr", force=True)
+    else:
+        start_scan(source, force=True)
     return jsonify({"ok":True})
 
 @app.get("/api/scan-status")