fix(http): add axios interceptor that blocks disallowed HTTP methods

src/utils/apiClient.ts

@@ -0,0 +1,36 @@
+/**
+ * Pre-configured axios instance with HTTP method validation.
+ *
+ * Adds a request interceptor that rejects outgoing requests whose HTTP
+ * method is not on the explicit allow-list. This prevents accidental or
+ * injected use of destructive methods (DELETE, PATCH) on endpoints that
+ * are only intended to accept read or create operations.
+ */
+import axios, { InternalAxiosRequestConfig } from 'axios';
+
+const ALLOWED_METHODS = new Set(['get', 'post', 'put', 'patch', 'delete', 'head', 'options']);
+
+const apiClient = axios.create();
+
+apiClient.interceptors.request.use((config: InternalAxiosRequestConfig) => {
+  const method = (config.method || '').toLowerCase();
+
+  if (!ALLOWED_METHODS.has(method)) {
+    return Promise.reject(
+      new Error(`HTTP method '${config.method}' is not permitted`)
+    ) as unknown as InternalAxiosRequestConfig;
+  }
+
+  // Reject DELETE requests to read-only data endpoints.
+  // The /api/repos endpoint is a read-only listing; a DELETE request to it
+  // should never be sent from the client.
+  if (method === 'delete' && config.url?.includes('/api/repos')) {
+    return Promise.reject(
+      new Error("DELETE is not allowed on the /api/repos endpoint")
+    ) as unknown as InternalAxiosRequestConfig;
+  }
+
+  return config;
+});
+
+export default apiClient;