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prunes superseded rules (pre-existing dead rules protected), a selector-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>

.github/workflows/ci.yml

@@ -6,6 +6,10 @@ on:
   pull_request:
     branches: [main]
   workflow_dispatch:
+  # Nightly full live-e2e matrix. The smoke groups already gate every PR; the
+  # full sweep is too slow for that, so it runs once a day against main.
+  schedule:
+    - cron: '0 7 * * *'
 
 concurrency:
   group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.ref }}
@@ -157,14 +161,16 @@ jobs:
     name: live-e2e smoke (${{ matrix.group }})
     runs-on: ubuntu-latest
     needs: changes
-    if: needs.changes.outputs.live_e2e == 'true' && github.event_name != 'workflow_dispatch'
+    if: needs.changes.outputs.live_e2e == 'true' && github.event_name != 'workflow_dispatch' && github.event_name != 'schedule'
     timeout-minutes: 15
     strategy:
       fail-fast: true
       matrix:
         include:
           - group: platform
-            fixtures: astro-vite7,nextjs-app-router,vite8-sveltekit
+            fixtures: astro-vite7,monorepo-nested-vite,nextjs-app-router,vite8-sveltekit
+          - group: svelte
+            fixtures: vite8-sveltekit-stateful
           - group: react
             fixtures: vite8-react-css-modules,vite8-react-insert,vite8-react-plain
     steps:
@@ -225,14 +231,16 @@ jobs:
     name: live-e2e full (${{ matrix.group }})
     runs-on: ubuntu-latest
     needs: changes
-    if: needs.changes.outputs.live_e2e == 'true' && github.event_name == 'workflow_dispatch'
+    if: needs.changes.outputs.live_e2e == 'true' && (github.event_name == 'workflow_dispatch' || github.event_name == 'schedule')
     timeout-minutes: 25
     strategy:
       fail-fast: true
       matrix:
         include:
           - group: platform
-            fixtures: astro-vite7,nextjs-app-router,vite8-sveltekit
+            fixtures: astro-vite7,monorepo-nested-vite,nextjs-app-router
+          - group: svelte
+            fixtures: vite8-sveltekit,vite8-sveltekit-stateful
           - group: react-a
             fixtures: vite8-https,vite8-react-base-path,vite8-react-csp-meta,vite8-react-css-modules,vite8-react-emotion
           - group: react-b