Add 30-second request timeout to API client

Prevents requests from hanging indefinitely when the server is
unreachable or slow to respond.

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

Author: toddaheath

src/shed-builder-ui/src/services/api.ts

@@ -15,6 +15,7 @@ const API_BASE = import.meta.env.VITE_API_BASE_URL ?? '/api/v1';
 
 const client = axios.create({
   baseURL: API_BASE,
+  timeout: 30000,
 });
 
 const TOKEN_STORAGE = 'shed-builder-token';