Live v2: root manifest, mount-ack protocol, AST scaffolder, mechanical accept

A ground-up hardening of live mode, driven by a production session in a
nested-app monorepo that hit six distinct failure classes. Full design
rationale in docs/LIVE-REWRITE-PLAN.md; every Codex-reported failure now
has a mechanical fix and a regression test.

Roots: live/roots.mjs resolves appRoot/repoRoot/contextRoot once at boot
(keyed on dev-server configs, not monorepo brand markers), persists a
manifest, and every live CLI re-anchors onto it at startup, so a helper
run from the wrong directory can no longer fork session state. Context
files are discovered upward to the git root.

Render truth: variant_mounted / variant_mount_failed events give the
journal per-variant mount state; failures reach the agent's poll queue,
raise a persistent error card with Retry (no more localStorage wipe), and
an attach probe names root/dev-server mismatches explicitly. The browser
rehydrates from the server when localStorage is gone.

Svelte: the scaffolder now parses with the app's own svelte 5 compiler.
Control flow survives (an each collection crosses the contract as one
structured prop), keyed each blocks hydrate synthetic keys, and anything
a detached preview cannot support falls back to source-preview instead of
shipping a wrong scaffold. Preview modules live in per-publish revision
directories, defeating stale transform caches.

Accept: CSS is reconciled, not appended. Matching selectors are replaced,
params bake from params.json kinds, the compiler's unused-selector pass
prunes superseded rules (pre-existing dead rules protected), a selector-
loss postcondition refuses any write that would drop hand-written rules,
and live-complete refuses to finish while live plumbing remains in source.

Also: framework registry (live/frameworks/) with a crash-safe injection
journal, session-store snapshot caching with read-only reads, protocol
enum consolidation, steer Send button, honest DESIGN-panel empty states.

Testing: new unit suites (roots, AST scaffolder, accept CSS, accept
pipeline, framework conformance); e2e now fails on preview-tree 404s,
proves computed-style mount for every variant, drives the Tune panel
through baked params, and injects failures (broken mounts, republish,
storage loss). New runtime fixtures: monorepo-nested-vite (repo root !=
app root) and vite8-sveltekit-stateful (each blocks + state). Nightly
full-matrix cron. An independent adversarial review pass preceded this
commit; its blocker and major findings are fixed and regression-tested.

This work was produced with AI assistance (Claude Code).

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

skill/scripts/live-status.mjs

@@ -5,7 +5,8 @@
 
 import { createLiveSessionStore } from './live/session-store.mjs';
 import { readLiveServerInfo } from './lib/impeccable-paths.mjs';
-import { manualApplyResumeHint } from './live-resume.mjs';
+import { manualApplyResumeHint, mountFailureAction, renderSummary } from './live-resume.mjs';
+import { enterLiveRoot } from './live/roots.mjs';
 
 function readServerInfo() {
   return readLiveServerInfo(process.cwd())?.info || null;
@@ -28,6 +29,8 @@ export async function statusCli() {
   const store = createLiveSessionStore({ cwd: process.cwd() });
   const activeSessions = store.listActiveSessions();
   const manualApply = findPendingManualApply(server, activeSessions);
+  const sessions = server?.activeSessions || activeSessions;
+  const renderFailure = sessions.find((session) => session?.renderState === 'failed') || null;
   const payload = {
     liveServer: server ? {
       status: server.status,
@@ -36,14 +39,16 @@ export async function statusCli() {
       agentPolling: server.agentPolling,
       pendingEvents: server.pendingEvents,
     } : null,
-    activeSessions: server?.activeSessions || activeSessions,
-    recoveryHint: recoveryHint({ server, manualApply }),
+    activeSessions: sessions,
+    render: sessions.map((session) => ({ id: session?.id ?? null, ...renderSummary(session) })),
+    recoveryHint: recoveryHint({ server, manualApply, renderFailure }),
   };
   console.log(JSON.stringify(payload, null, 2));
 }
 
-function recoveryHint({ server, manualApply }) {
+function recoveryHint({ server, manualApply, renderFailure }) {
   if (manualApply) return manualApplyResumeHint(manualApply);
+  if (renderFailure) return mountFailureAction(renderFailure);
   if (server) {
     return 'Run live-poll.mjs to continue pending work, or live-complete.mjs --id <session> after manual cleanup.';
   }
@@ -61,5 +66,6 @@ function findPendingManualApply(server, activeSessions) {
 
 const _running = process.argv[1];
 if (_running?.endsWith('live-status.mjs') || _running?.endsWith('live-status.mjs/')) {
+  enterLiveRoot();
   statusCli();
 }