fix: normalize api_get/api_post endpoints to prevent leading-slash path issues

The httpx client's base_url includes /api, so leading slashes in
endpoints cause httpx to treat them as absolute paths from the host
root, bypassing the base path. This made api_get("/api/events") 404
and api_get("/events") hit the wrong path.

Added _normalize_endpoint() that strips leading slashes and any
accidental /api/ prefix, so all three forms work identically:
  api_get("events"), api_get("/events"), api_get("/api/events")

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: kingpanther13

src/ha_mcp/tools/tools_code.py

@@ -93,14 +93,27 @@ async def _run_sandboxed_code(
     """
     call_count = 0
 
+    def _normalize_endpoint(endpoint: str) -> str:
+        """Normalize endpoint to be relative to the httpx base URL (/api).
+
+        Leading slashes cause httpx to treat the path as absolute from the
+        host root, bypassing the /api base path.  Strip them (and any
+        accidental /api/ prefix) so all three forms work identically:
+        "events", "/events", "/api/events" → "events".
+        """
+        ep = endpoint.lstrip("/")
+        if ep.startswith("api/"):
+            ep = ep[4:]
+        return ep
+
     async def _api_get(endpoint: str) -> Any:
         """GET request to Home Assistant REST API."""
         nonlocal call_count
         call_count += 1
         if call_count > settings.code_mode_max_invocations:
             return {"error": f"API call limit exceeded ({settings.code_mode_max_invocations})"}
         try:
-            response = await client.httpx_client.request("GET", endpoint)
+            response = await client.httpx_client.request("GET", _normalize_endpoint(endpoint))
             try:
                 return response.json()
             except json.JSONDecodeError:
@@ -118,7 +131,7 @@ async def _api_post(endpoint: str, data: dict[str, Any] | None = None) -> Any:
             post_kwargs: dict[str, Any] = {}
             if data is not None:
                 post_kwargs["json"] = data
-            response = await client.httpx_client.request("POST", endpoint, **post_kwargs)
+            response = await client.httpx_client.request("POST", _normalize_endpoint(endpoint), **post_kwargs)
             try:
                 return response.json()
             except json.JSONDecodeError: