fix: restore PipeWire combined source automatically on startup

Save mic/monitor device names to pipewire-modules.json alongside module IDs.
On startup, recreate transkriptor-combined if not already loaded.

main.py

@@ -49,6 +49,45 @@ async def settingsjs():
     return FileResponse(str(FRONTEND_DIR / "settings.js"))
 
 
+# ── PipeWire combined source restore ──────────────────────────────────────────
+
+def _restore_pipewire_combined():
+    """Recreate transkriptor-combined.monitor on startup if it was previously configured."""
+    import json, subprocess, logging
+    state_path = Path(os.path.expanduser("~/.config/tueit-transcriber/pipewire-modules.json"))
+    if not state_path.exists():
+        return
+    try:
+        data = json.loads(state_path.read_text())
+        mic = data.get("mic")
+        monitor = data.get("monitor")
+        if not mic or not monitor:
+            return
+        sources = subprocess.check_output(
+            ["pactl", "list", "sources", "short"], stderr=subprocess.DEVNULL, timeout=5
+        ).decode()
+        if "transkriptor-combined.monitor" in sources:
+            return  # already loaded
+        sink_id = subprocess.check_output([
+            "pactl", "load-module", "module-null-sink",
+            "sink_name=transkriptor-combined",
+            "sink_properties=device.description=Transkriptor Combined",
+        ], timeout=5).decode().strip()
+        mic_id = subprocess.check_output([
+            "pactl", "load-module", "module-loopback",
+            f"source={mic}", "sink=transkriptor-combined",
+        ], timeout=5).decode().strip()
+        mon_id = subprocess.check_output([
+            "pactl", "load-module", "module-loopback",
+            f"source={monitor}", "sink=transkriptor-combined",
+        ], timeout=5).decode().strip()
+        ids = [int(sink_id), int(mic_id), int(mon_id)]
+        state_path.write_text(json.dumps({"ids": ids, "mic": mic, "monitor": monitor}))
+        logging.getLogger(__name__).info("Restored PipeWire combined source (ids: %s)", ids)
+    except Exception as e:
+        logging.getLogger(__name__).warning("Could not restore PipeWire combined source: %s", e)
+
+
 # ── PID file ───────────────────────────────────────────────────────────────────
 
 def write_pid(pid_path: str):
@@ -145,6 +184,7 @@ if __name__ == "__main__":
     pid_path = cfg.get("pid_file", os.path.expanduser("~/.local/run/tueit-transcriber.pid"))
 
     write_pid(pid_path)
+    _restore_pipewire_combined()
     signal.signal(signal.SIGUSR1, _sigusr1_handler)
 
     uvicorn_cfg = uvicorn.Config(app, host=host, port=port, log_level="debug")