test(live): add full-cycle E2E framework-fixture suite with pluggable agent

19 fixtures (11 styling/build variants + 4 conditional-render scenarios + 4
meta-frameworks) drive the entire user flow end-to-end: handshake, pick,
configure, Go, cycle, accept, carbonize cleanup. Each fixture installs real
deps, boots the framework dev server, and runs Playwright Chromium against a
deterministic fake agent that produces realistic variants (colocated style
with @scope rules, full data-impeccable-params manifests covering range +
steps + toggle, JSX/HTML/Svelte syntax-aware rendering).

The agent is pluggable via a one-method interface — generateVariants(event) —
so a future LLM-backed agent slots in by implementing the same shape. The
orchestrator handles wrap, file write, accept, and carbonize cleanup
deterministically regardless of which agent is plugged in.

Schema extensions (tests/framework-fixtures/README.md): runtime block adds
preActions / reloadProbe / pickSelector / scheme / ignoreHTTPSErrors so
fixtures can drive conditional UI (modal, tab, route) before pick and verify
the carbonized variant survives a reload.

Static fixture suite filtered to skip dirs without fixture.json so empty
scaffold dirs no longer break discovery. Total: 178 static checks, 19 E2E
full cycles, ~107s wall clock for the E2E suite.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

tests/framework-fixtures/vite8-https/files/src/main.jsx

@@ -0,0 +1,10 @@
+import { StrictMode } from 'react';
+import { createRoot } from 'react-dom/client';
+import App from './App.jsx';
+import './styles.css';
+
+createRoot(document.getElementById('root')).render(
+  <StrictMode>
+    <App />
+  </StrictMode>,
+);