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/mood.py

@@ -1,6 +1,7 @@
 """Mood management routes: DM mood, per-server mood, available moods, test mood."""
 
 from fastapi import APIRouter
+from fastapi.responses import JSONResponse
 import globals
 from server_manager import server_manager
 from routes.models import MoodSetRequest
@@ -23,7 +24,7 @@ async def set_mood_endpoint(data: MoodSetRequest):
     # This endpoint now operates on DM_MOOD
     from utils.moods import MOOD_EMOJIS
     if data.mood not in MOOD_EMOJIS:
-        return {"status": "error", "message": f"Mood '{data.mood}' not recognized. Available moods: {', '.join(MOOD_EMOJIS.keys())}"}
+        return JSONResponse(status_code=400, content={"status": "error", "message": f"Mood '{data.mood}' not recognized. Available moods: {', '.join(MOOD_EMOJIS.keys())}"})
 
     # Update DM mood (DMs don't have nicknames, so no nickname update needed)
     globals.DM_MOOD = data.mood
@@ -94,13 +95,13 @@ async def set_server_mood_endpoint(guild_id: int, data: MoodSetRequest):
     # Check if server exists
     if guild_id not in server_manager.servers:
         logger.warning(f"Server {guild_id} not found in server_manager.servers")
-        return {"status": "error", "message": "Server not found"}
+        return JSONResponse(status_code=404, content={"status": "error", "message": "Server not found"})
 
     # Check if mood is valid
     from utils.moods import MOOD_EMOJIS
     if data.mood not in MOOD_EMOJIS:
         logger.warning(f"Mood '{data.mood}' not found in MOOD_EMOJIS. Available moods: {list(MOOD_EMOJIS.keys())}")
-        return {"status": "error", "message": f"Mood '{data.mood}' not recognized. Available moods: {', '.join(MOOD_EMOJIS.keys())}"}
+        return JSONResponse(status_code=400, content={"status": "error", "message": f"Mood '{data.mood}' not recognized. Available moods: {', '.join(MOOD_EMOJIS.keys())}"})
 
     success = server_manager.set_server_mood(guild_id, data.mood)
     logger.debug(f"Server mood set result: {success}")
@@ -113,7 +114,7 @@ async def set_server_mood_endpoint(guild_id: int, data: MoodSetRequest):
         return {"status": "ok", "new_mood": data.mood, "guild_id": guild_id}
 
     logger.warning(f"set_server_mood returned False for unknown reason")
-    return {"status": "error", "message": "Failed to set server mood"}
+    return JSONResponse(status_code=500, content={"status": "error", "message": "Failed to set server mood"})
 
 
 @router.post("/servers/{guild_id}/mood/reset")
@@ -124,7 +125,7 @@ async def reset_server_mood_endpoint(guild_id: int):
     # Check if server exists
     if guild_id not in server_manager.servers:
         logger.warning(f"Server {guild_id} not found in server_manager.servers")
-        return {"status": "error", "message": "Server not found"}
+        return JSONResponse(status_code=404, content={"status": "error", "message": "Server not found"})
 
     logger.debug(f"Server validation passed, calling set_server_mood")
     success = server_manager.set_server_mood(guild_id, "neutral")
@@ -138,7 +139,7 @@ async def reset_server_mood_endpoint(guild_id: int):
         return {"status": "ok", "new_mood": "neutral", "guild_id": guild_id}
 
     logger.warning(f"set_server_mood returned False for unknown reason")
-    return {"status": "error", "message": "Failed to reset server mood"}
+    return JSONResponse(status_code=500, content={"status": "error", "message": "Failed to reset server mood"})
 
 
 @router.get("/servers/{guild_id}/mood/state")
@@ -147,7 +148,7 @@ def get_server_mood_state(guild_id: int):
     mood_state = server_manager.get_server_mood_state(guild_id)
     if mood_state:
         return {"status": "ok", "guild_id": guild_id, "mood_state": mood_state}
-    return {"status": "error", "message": "Server not found"}
+    return JSONResponse(status_code=404, content={"status": "error", "message": "Server not found"})
 
 
 # ========== Misc Mood ==========
@@ -166,7 +167,7 @@ async def test_mood_change(guild_id: int, data: MoodSetRequest):
 
     # Check if server exists
     if guild_id not in server_manager.servers:
-        return {"status": "error", "message": f"Server {guild_id} not found"}
+        return JSONResponse(status_code=404, content={"status": "error", "message": f"Server {guild_id} not found"})
 
     server_config = server_manager.get_server_config(guild_id)
     logger.debug(f"TEST: Server config found: {server_config.guild_name if server_config else 'None'}")
@@ -189,4 +190,4 @@ async def test_mood_change(guild_id: int, data: MoodSetRequest):
 
         return {"status": "ok", "message": f"Test mood change completed", "success": success}
 
-    return {"status": "error", "message": "Mood change failed"}
+    return JSONResponse(status_code=500, content={"status": "error", "message": "Mood change failed"})