feat(auth): inject MCP_INSPECTOR_API_TOKEN into served index.html (#1378) (#1382)

* feat(auth): inject MCP_INSPECTOR_API_TOKEN into served index.html (#1378)

Reloading the web client at the bare URL (no `?MCP_INSPECTOR_API_TOKEN=…`
query string) with empty sessionStorage made every `/api/*` request 401 —
the browser had no way to recover the backend's auth token.

Embed the token into `index.html` on every page load so the browser no
longer depends on the query string surviving navigation:

- New shared helper `clients/web/server/inject-auth-token.ts` embeds
  `<script>window.__INSPECTOR_API_TOKEN__ = "…"</script>` (escaped against
  `</script>` injection; no-op when auth is dangerously omitted).
- Dev: the Vite plugin injects via `transformIndexHtml`.
- Prod: the Hono server injects on the `/` route.
- `App.tsx` `getAuthToken()` now reads the injected global first, then the
  query string, then sessionStorage (both fallbacks preserved).
- Shared global name lives in `INSPECTOR_API_TOKEN_GLOBAL`
  (`core/mcp/remote/constants.ts`).

Tests: helper unit coverage + an integration test exercising the real
prod server's `/` → `/api/*` flow (injected token authenticates; missing
token 401s). AGENTS.md documents the token-recovery order.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

* fix(auth): inject token into prod SPA fallback + prime sessionStorage + no-store (#1378)

Addresses code-review feedback on the token-injection PR:

- Prod `server.ts` SPA deep-link fallback (e.g. `/oauth/callback`) previously
  served the raw index.html off disk via serveStatic, bypassing injection — so
  a bookmark/reload at a non-`/` route with empty sessionStorage would 401.
  Route the SPA fallback through the same `serveIndexHtml` (inject) helper;
  real static assets (paths with a dot) still serve verbatim. Dev already
  injected on every HTML serve via Vite `transformIndexHtml`.
- `getAuthToken()` now persists the injected `window.__INSPECTOR_API_TOKEN__`
  to sessionStorage (not just the URL-param branch), priming the backstop for
  any later navigation that loses the global.
- Injected HTML responses now send `Cache-Control: no-store`, so a page
  carrying a token isn't cached and served stale after a restart regenerates
  the token.

Integration tests added: SPA fallback (`/oauth/callback`) carries the token,
`Cache-Control: no-store` on injected HTML, real assets served verbatim, and
unknown `/api` routes 404 rather than falling through to the HTML shell.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

core/mcp/remote/constants.ts

@@ -12,3 +12,14 @@ export const API_SERVER_ENV_VARS = {
    */
   AUTH_TOKEN: "MCP_INSPECTOR_API_TOKEN",
 } as const;
+
+/**
+ * Name of the global property the web backend injects into `index.html` so the
+ * browser can recover the API token without depending on the
+ * `?MCP_INSPECTOR_API_TOKEN=…` query string surviving navigation (or a manual
+ * reload at the bare URL). The dev Vite plugin and the prod Hono server both
+ * embed `<script>window.__INSPECTOR_API_TOKEN__ = "…"</script>` on the served
+ * page; `App.tsx`'s `getAuthToken()` reads it ahead of the URL / sessionStorage
+ * fallbacks. See `clients/web/server/inject-auth-token.ts`.
+ */
+export const INSPECTOR_API_TOKEN_GLOBAL = "__INSPECTOR_API_TOKEN__";