fix: prefix axios baseURL with import.meta.env.BASE_URL for sub-path routing

/api/v1 (absolute) was routing to menagerie.circuitforge.tech/api/v1 which
hit the global @api_no_session gate instead of the Magpie API at /magpie/api*.

Using import.meta.env.BASE_URL (set to /magpie/ at build time via VITE_BASE_URL)
produces /magpie/api/v1 in production and /api/v1 in dev (where Vite proxies /api).

Also adds vite-env.d.ts so TypeScript recognises import.meta.env.

frontend/src/services/api.ts

@@ -1,6 +1,6 @@
 import axios from 'axios'
 
-const http = axios.create({ baseURL: '/api/v1' })
+const http = axios.create({ baseURL: `${import.meta.env.BASE_URL}api/v1` })
 
 // ------------------------------------------------------------------ //
 // Types

frontend/src/vite-env.d.ts

@@ -0,0 +1 @@
+/// <reference types="vite/client" />