feat: add proper HTTP status codes to all API error responses

- 217 error returns across 18 route files + api.py now use JSONResponse
  with appropriate HTTP status codes instead of returning HTTP 200
- Status code distribution: 500 (121), 400 (39), 503 (28), 404 (24), 409 (3), 502 (2)
- Fixed language.py tuple-return bug (was serializing as JSON array)
- Fixed bare except clauses in bipolar_mode.py and voice.py
- Body-level error schemas preserved (status/error + success/error patterns)
  so web UI continues working without changes
- chat.py (SSE) unchanged: errors sent within stream protocol
- All 170 tests pass

bot/routes/image_generation.py

@@ -2,7 +2,7 @@
 
 import os
 from fastapi import APIRouter
-from fastapi.responses import FileResponse
+from fastapi.responses import FileResponse, JSONResponse
 from utils.logger import get_logger
 
 logger = get_logger('api')
@@ -16,7 +16,7 @@ async def manual_image_generation(req: dict):
     try:
         prompt = req.get("prompt", "").strip()
         if not prompt:
-            return {"status": "error", "message": "Prompt is required"}
+            return JSONResponse(status_code=400, content={"status": "error", "message": "Prompt is required"})
 
         from utils.image_generation import generate_image_with_comfyui
         image_path = await generate_image_with_comfyui(prompt)
@@ -24,10 +24,10 @@ async def manual_image_generation(req: dict):
         if image_path:
             return {"status": "ok", "message": f"Image generated successfully", "image_path": image_path}
         else:
-            return {"status": "error", "message": "Failed to generate image"}
+            return JSONResponse(status_code=500, content={"status": "error", "message": "Failed to generate image"})
 
     except Exception as e:
-        return {"status": "error", "message": f"Error: {e}"}
+        return JSONResponse(status_code=500, content={"status": "error", "message": f"Error: {e}"})
 
 
 @router.get("/image/status")
@@ -39,7 +39,7 @@ async def get_image_generation_status():
         return {"status": "ok", **status}
 
     except Exception as e:
-        return {"status": "error", "message": f"Error: {e}"}
+        return JSONResponse(status_code=500, content={"status": "error", "message": f"Error: {e}"})
 
 
 @router.post("/image/test-detection")
@@ -48,7 +48,7 @@ async def test_image_detection(req: dict):
     try:
         message = req.get("message", "").strip()
         if not message:
-            return {"status": "error", "message": "Message is required"}
+            return JSONResponse(status_code=400, content={"status": "error", "message": "Message is required"})
 
         from utils.image_generation import detect_image_request
         is_image_request, extracted_prompt = await detect_image_request(message)
@@ -61,7 +61,7 @@ async def test_image_detection(req: dict):
         }
 
     except Exception as e:
-        return {"status": "error", "message": f"Error: {e}"}
+        return JSONResponse(status_code=500, content={"status": "error", "message": f"Error: {e}"})
 
 
 @router.get("/image/view/{filename}")
@@ -88,7 +88,7 @@ async def view_generated_image(filename: str):
 
         if not image_path:
             logger.warning(f"Image not found anywhere: {filename}")
-            return {"status": "error", "message": f"Image not found: {filename}"}
+            return JSONResponse(status_code=404, content={"status": "error", "message": f"Image not found: {filename}"})
 
         # Determine content type based on file extension
         ext = filename.lower().split('.')[-1]
@@ -105,4 +105,4 @@ async def view_generated_image(filename: str):
 
     except Exception as e:
         logger.error(f"Error serving image: {e}")
-        return {"status": "error", "message": f"Error serving image: {e}"}
+        return JSONResponse(status_code=500, content={"status": "error", "message": f"Error serving image: {e}"})