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/bipolar_mode.py

@@ -2,6 +2,7 @@
 
 import asyncio
 from fastapi import APIRouter
+from fastapi.responses import JSONResponse
 import globals
 from routes.models import BipolarTriggerRequest
 from utils.logger import get_logger
@@ -106,23 +107,23 @@ def trigger_argument(data: BipolarTriggerRequest):
     try:
         channel_id = int(data.channel_id)
     except ValueError:
-        return {"status": "error", "message": "Invalid channel ID format"}
+        return JSONResponse(status_code=400, content={"status": "error", "message": "Invalid channel ID format"})
 
     message_id = None
     if data.message_id:
         try:
             message_id = int(data.message_id)
         except ValueError:
-            return {"status": "error", "message": "Invalid message ID format"}
+            return JSONResponse(status_code=400, content={"status": "error", "message": "Invalid message ID format"})
 
     if not is_bipolar_mode():
-        return {"status": "error", "message": "Bipolar mode is not enabled"}
+        return JSONResponse(status_code=400, content={"status": "error", "message": "Bipolar mode is not enabled"})
 
     if is_argument_in_progress(channel_id):
-        return {"status": "error", "message": "An argument is already in progress in this channel"}
+        return JSONResponse(status_code=409, content={"status": "error", "message": "An argument is already in progress in this channel"})
 
     if not globals.client or not globals.client.loop or not globals.client.loop.is_running():
-        return {"status": "error", "message": "Discord client not ready"}
+        return JSONResponse(status_code=503, content={"status": "error", "message": "Discord client not ready"})
 
     # If message_id is provided, use the message-based trigger
     if message_id:
@@ -145,7 +146,7 @@ def trigger_argument(data: BipolarTriggerRequest):
     # Otherwise, find the channel and trigger normally
     channel = globals.client.get_channel(channel_id)
     if not channel:
-        return {"status": "error", "message": f"Channel {channel_id} not found"}
+        return JSONResponse(status_code=404, content={"status": "error", "message": f"Channel {channel_id} not found"})
 
     # Trigger the argument
     globals.client.loop.create_task(force_trigger_argument(channel, globals.client, data.context))
@@ -168,19 +169,19 @@ def trigger_dialogue(data: dict):
 
     message_id_str = data.get("message_id")
     if not message_id_str:
-        return {"status": "error", "message": "Message ID is required"}
+        return JSONResponse(status_code=400, content={"status": "error", "message": "Message ID is required"})
 
     # Parse message ID
     try:
         message_id = int(message_id_str)
     except ValueError:
-        return {"status": "error", "message": "Invalid message ID format"}
+        return JSONResponse(status_code=400, content={"status": "error", "message": "Invalid message ID format"})
 
     if not is_bipolar_mode():
-        return {"status": "error", "message": "Bipolar mode is not enabled"}
+        return JSONResponse(status_code=400, content={"status": "error", "message": "Bipolar mode is not enabled"})
 
     if not globals.client or not globals.client.loop or not globals.client.loop.is_running():
-        return {"status": "error", "message": "Discord client not ready"}
+        return JSONResponse(status_code=503, content={"status": "error", "message": "Discord client not ready"})
 
     async def trigger_dialogue_task():
         try:
@@ -191,7 +192,7 @@ def trigger_dialogue(data: dict):
                     try:
                         message = await channel.fetch_message(message_id)
                         break
-                    except:
+                    except Exception:
                         continue
 
             if not message:
@@ -272,7 +273,7 @@ def cleanup_bipolar_webhooks():
     from utils.bipolar_mode import cleanup_webhooks
 
     if not globals.client or not globals.client.loop or not globals.client.loop.is_running():
-        return {"status": "error", "message": "Discord client not ready"}
+        return JSONResponse(status_code=503, content={"status": "error", "message": "Discord client not ready"})
 
     globals.client.loop.create_task(cleanup_webhooks(globals.client))
     return {"status": "ok", "message": "Webhook cleanup started"}