Add TanStack Router + Start support to live mode

Live mode had no TanStack coverage: a TanStack Start user hit disconnects
and static previews because there is no static index.html to inject and no
adapter for the SSR root document.

- New tanstack-adapter.mjs, modeled on the SvelteKit/Nuxt adapters: detects
  a TanStack Start project (@tanstack/react-start + src/routes/__root.tsx)
  and patches the __root document to mount a generated dev-only React
  component (src/impeccable/ImpeccableLiveRoot) that appends the live bundle
  on the client after hydration, carrying the ?token= param via
  buildLiveScriptSrc. Patch/unpatch round-trips byte-for-byte and is
  idempotent; refuses to clobber an unmanaged file at the component path.
- Wire detection into live-inject.mjs (insert + remove + gitignore),
  ordered so SvelteKit/Nuxt win and a plain TanStack Router SPA falls
  through to the baseline Vite index.html path.
- tanstack-router-vite fixture (baseline, no adapter) and tanstack-start
  fixture (SSR adapter), both with runtime blocks. Both pass the full
  live-e2e cycle (handshake, steer, pick, Go, cycle, accept, carbonize,
  reloadProbe).
- Unit tests for detection + patch round-trip + apply/remove; tanstack-start
  branches in framework-fixtures.test.mjs; live.md framework table + adapter note.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

tests/framework-fixtures/tanstack-start/fixture.json

@@ -0,0 +1,40 @@
+{
+  "name": "Vite 8 + TanStack Start (SSR, root-document adapter)",
+  "config": {
+    "files": ["src/routes/__root.tsx"],
+    "insertBefore": "<Scripts",
+    "commentSyntax": "jsx"
+  },
+  "sourceFiles": [
+    "src/routes/__root.tsx",
+    "src/routes/index.tsx",
+    "src/router.tsx",
+    "vite.config.js"
+  ],
+  "generatedFiles": [],
+  "wrapCases": [
+    {
+      "name": "wraps index hero in routes/index.tsx",
+      "args": { "classes": "hero-title", "tag": "h1" },
+      "expectedFile": "src/routes/index.tsx"
+    }
+  ],
+  "runtime": {
+    "styling": "plain-css",
+    "install": ["npm", "install", "--no-audit", "--no-fund", "--loglevel=error"],
+    "devCommand": ["npm", "run", "dev"],
+    "readyPattern": "Local:\\s+https?://[^:]+:(\\d+)",
+    "readyTimeoutMs": 180000,
+    "pickSelector": "h1.hero-title",
+    "reloadProbe": {
+      "expectSelector": "h1.hero-title"
+    },
+    "probe": {
+      "expectLiveInit": true,
+      "expectConsoleClean": true
+    },
+    "steer": {
+      "sourceFile": "src/routes/index.tsx"
+    }
+  }
+}