Claude Code: add HTTPException handlers to error_handlers.py

Added FastAPI exception handlers (http_exception_handler and
generic_exception_handler) to properly handle HTTPException and
generic exceptions in the FastAPI app.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

error_handlers.py

@@ -7,6 +7,53 @@ import json
 import os
 from datetime import datetime
 from typing import Dict, Any, Optional
+from fastapi import HTTPException, Request
+from fastapi.responses import JSONResponse
+
+
+async def http_exception_handler(request: Request, exc: HTTPException) -> JSONResponse:
+    """
+    FastAPI exception handler for HTTPException.
+
+    Args:
+        request: The incoming request.
+        exc: The HTTPException that was raised.
+
+    Returns:
+        JSONResponse with error details.
+    """
+    return JSONResponse(
+        status_code=exc.status_code,
+        content={
+            "error": True,
+            "message": exc.detail,
+            "status_code": exc.status_code,
+            "agent": "cain"
+        },
+    )
+
+
+async def generic_exception_handler(request: Request, exc: Exception) -> JSONResponse:
+    """
+    FastAPI exception handler for generic exceptions.
+
+    Args:
+        request: The incoming request.
+        exc: The Exception that was raised.
+
+    Returns:
+        JSONResponse with error details.
+    """
+    return JSONResponse(
+        status_code=500,
+        content={
+            "error": True,
+            "message": "Internal server error",
+            "detail": str(exc),
+            "type": type(exc).__name__,
+            "agent": "cain"
+        },
+    )
 
 
 # Configuration paths