fix(agent): pin vite + @vitejs/plugin-react via overrides (#1330)

`@wxt-dev/module-react@1.2.2` accepts `@vitejs/plugin-react`
`^4.4.1 || ^5.0.0 || ^6.0.0`, and bun was resolving to 6.0.1, which
declares `vite ^8.0.0` as a peer. That cascaded vite to 8.0.6, which
swaps in Rolldown by default, and the dev server then refuses to
resolve our wxt-generated `app.html` / `sidepanel.html` entry points
(rolldown UNRESOLVED_ENTRY).

Pin `@vitejs/plugin-react ^5.0.0` and `vite ^7.0.0` via root
overrides. `bun run typecheck`, `bun fallow`, and the mcp-manager
test suite stay green.

Author: DaniAkash