Add persistent default temp directory setting with web UI

- Add settings.json persistence (load/save) in backend
- Add GET/POST /api/settings endpoints for default_temp_dir
- Add Default Temp Directory config UI in Temporary Storage section
- Auto-fallback: jobs use saved default if no per-job temp_dir set
- Per-job Advanced Options placeholder syncs with saved default
- Add settings.json to .gitignore for per-machine config

app/main.py

@@ -86,6 +86,29 @@ main_loop = None
 
 JOBS_FILE = os.path.join(upscaler.BASE_DIR, "jobs.json")
 
+SETTINGS_FILE = os.path.join(upscaler.BASE_DIR, "settings.json")
+
+def load_settings() -> dict:
+    """Load persistent app settings from settings.json"""
+    defaults = {"default_temp_dir": ""}
+    if os.path.exists(SETTINGS_FILE):
+        try:
+            with open(SETTINGS_FILE, "r") as f:
+                saved = json.load(f)
+                defaults.update(saved)
+        except Exception as e:
+            print(f"Error loading settings: {e}")
+    return defaults
+
+def save_settings(settings: dict):
+    """Save persistent app settings to settings.json"""
+    try:
+        with open(SETTINGS_FILE, "w") as f:
+            json.dump(settings, f, indent=4)
+    except Exception as e:
+        print(f"Error saving settings: {e}")
+
+
 def load_jobs_db():
     global jobs_db
     if os.path.exists(JOBS_FILE):
@@ -452,7 +475,7 @@ def start_upscale(req: StartUpscaleRequest):
         ai_face_restoration=req.ai_face_restoration,
         ai_rife_interpolation=req.ai_rife_interpolation,
         ai_audio_denoise=req.ai_audio_denoise,
-        temp_dir=req.temp_dir
+        temp_dir=req.temp_dir or load_settings().get("default_temp_dir") or None
     )
     
     jobs_db[job_id] = job
@@ -527,7 +550,7 @@ def start_upscale_batch(req: StartBatchUpscaleRequest):
             ai_face_restoration=req.ai_face_restoration,
             ai_rife_interpolation=req.ai_rife_interpolation,
             ai_audio_denoise=req.ai_audio_denoise,
-            temp_dir=req.temp_dir
+            temp_dir=req.temp_dir or load_settings().get("default_temp_dir") or None
         )
         jobs_db[job_id] = job
         job_queue.put(job_id)
@@ -1064,6 +1087,32 @@ def setup_webhook(req: WebhookSetupRequest):
     global_webhook_url = req.url
     return {"status": "success", "webhook_url": global_webhook_url}
 
+# ─── Settings Endpoints ─────────────────────────────────────────────
+class UpdateSettingsRequest(BaseModel):
+    default_temp_dir: str = ""
+
+@app.get("/api/settings")
+def get_settings():
+    """Get persistent app settings"""
+    settings = load_settings()
+    return settings
+
+@app.post("/api/settings")
+def update_settings(req: UpdateSettingsRequest):
+    """Update persistent app settings"""
+    settings = load_settings()
+    # Validate the directory path if provided
+    new_dir = req.default_temp_dir.strip()
+    if new_dir:
+        # Ensure the parent directory exists or can be created
+        try:
+            os.makedirs(new_dir, exist_ok=True)
+        except OSError as e:
+            raise HTTPException(status_code=400, detail=f"Invalid directory path: {e}")
+    settings["default_temp_dir"] = new_dir
+    save_settings(settings)
+    return {"status": "saved", "settings": settings}
+
 @app.get("/api/uploads/{filename}")
 def get_upload_file(filename: str):
     file_path = os.path.join(upscaler.UPLOAD_DIR, filename)