fix(proxy): use rewrite to route nested API paths to handler

Vercel's catch-all route ([...path].ts) wasn't matching nested paths
like /api/bugzilla/bug/123 when using the Vite framework. Changed to
use explicit rewrite rule that routes all /api/bugzilla/* paths to a
single handler at api/bugzilla.ts.

Also filters out '...path' query param that Vercel adds for catch-all
routes.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: msujaws

api/bugzilla/[...path].ts api/bugzilla.tsapi/bugzilla/[...path].ts renamed to api/bugzilla.ts

@@ -2,6 +2,12 @@
   "buildCommand": "npm run build",
   "outputDirectory": "dist",
   "framework": "vite",
+  "rewrites": [
+    {
+      "source": "/api/bugzilla/:path*",
+      "destination": "/api/bugzilla"
+    }
+  ],
   "headers": [
     {
       "source": "/(.*)",