fix(skills,cli): close four reproduced contract gaps from the CLI feedback digest (#2476)

* fix(cli): invalidate the skills nudge cache after a successful install/update/check

The passive "N skills out of date or missing" nudge reads a 24h config
cache that only the background check (on non-skills commands) ever wrote.
The skills commands themselves are excluded from the nudge pipeline, so a
successful `skills update`/install/check never refreshed or dropped the
cached verdict — the pre-install count kept printing on every other
command for up to 24h.

Reconcile commands now drop the cached verdict (counts + timestamp) so
the next command's background check re-runs for real. The offline
presence-only path deliberately keeps the cache: that run learned nothing
about freshness.

* fix(skills): win32-safe npx spawns in media-use + accurate whisper wording

The Whisper transcribe fallback and the Kokoro local-TTS delegation both
spawned a bare "npx" via execFileSync — on Windows npx is npx.cmd, which
spawn cannot exec, so both paths died with `spawnSync npx ENOENT`. Route
them through the skill's existing resolveSpawnCommand (node + npx-cli.js
on win32, no shell:true), same as the audio engine's TTS spawns.

Also corrects the "bundled with the hyperframes CLI" claim about
whisper.cpp: it is resolved from PATH / installed via Homebrew / built
from source with git+cmake on first use, and models download from
HuggingFace — nothing whisper is shipped in the package.

* feat(skills): canonical fully-silent marker + auth status exit-code docs

product-launch's Step 3.1 gate said "or the project is marked silent"
but nothing defined how to mark one, and audio.mjs unconditionally
retrieved BGM. Define the canonical marker — `music: none` in the
storyboard's top YAML block, plus no SCRIPT.md — and honor it:
audio generate produces nothing (removing stale audio_meta.json, since
absence is what assemble treats as silent), and `music: none` with
narration keeps TTS while turning BGM off.

Also documents the `auth status` exit-code contract (exit 1 while
signed out is the normal offline state, not a failure) in the
product-launch Step 0 note and the CLI skill's cloud reference.

* fix(skills): transient-init retry for standalone animation-map and contrast-report

The standalone helpers called initializeSession exactly once, so a valid
modular project — whose sub-composition timelines register asynchronously
— could hit the readiness deadline and die with the transient
"zero duration / Runtime ready: false" diagnostic the render pipeline
retries (probeStage). Add initializeSessionWithRetry to the shared
package-loader (both byte-identical copies): close the crashed session
and retry once with a fresh browser, gated by the engine's canonical
isTransientBrowserError — now re-exported from @hyperframes/producer,
with a frozen fallback pattern list for older published packages. The
"Runtime ready: true" fast-fail (a genuine authoring bug) still fails
without a retry.

* feat(skills): extend the fully-silent marker to faceless-explainer and pr-to-video

Both workflows reuse product-launch's audio model — their Step 3.1 gates
carried the same undefined "marked silent" phrase, and their (intentionally
identical) audio.mjs copies had the same unconditional BGM retrieve. Port
the `music: none` marker handling into both copies, define the marker in
their SKILL.md Step 3.1 and story-design references, and turn the
copies' "intentionally identical" header claim into a byte-identity pin
test so the next fix can't silently miss one of them.

* test(cli): reset the prune mock explicitly instead of relying on restoreAllMocks

The converge test's toHaveBeenCalledTimes(1) held only because vitest 3's
vi.restoreAllMocks() clears vi.fn() call state; vitest 4 restores spies
only, so the count would accumulate across tests and fail. Reset
pruneOrphanedLockEntries in beforeEach like the other manifest mocks —
passes under both vitest 3.2.4 (pinned) and vitest 4.

* test(skills): close review findings — package-loader pin, whisper win32 parity, quoted-none

Review follow-ups on #2476:

- package-loader.mjs byte-identity pin (the elevated concern): the two
  copies now carry initializeSessionWithRetry + FALLBACK_TRANSIENT_PATTERNS,
  exactly the shared-logic shape a future fix could land in one copy and
  miss in the other — same enforcement as the audio.mjs pin.
- whisper win32 call-site parity: runWhisper's npx resolution lifted into
  lib/npx-sync.mjs (resolveNpxInvocation, injectable params matching the
  localTtsGenerate idiom) with the same three-branch coverage as the
  Kokoro site — plus the hard-fail contract (throws actionably, since the
  whisper fallback has no next provider to fall through to).
- quoted music: "none" pin: the vendored storyboard parser strips matching
  quotes at parse time (stripQuotes), so the silent marker already accepts
  the quoted spelling — pinned so that stays true.

skills/hyperframes-animation/scripts/package-loader.mjs

@@ -73,6 +73,71 @@ export async function bundleCompositionForCapture(compiler, projectDir) {
   }
 }
 
+// ── Transient-init retry ─────────────────────────────────────────────────────
+// Frozen snapshot of the engine's TRANSIENT_BROWSER_ERROR_PATTERNS (see
+// packages/engine frameCapture.ts), used only when the imported
+// @hyperframes/producer predates the isTransientBrowserError re-export. The
+// last pattern is the load-bearing one for modular projects: sub-composition
+// timelines register asynchronously, so a first init attempt can time out as
+// "zero duration / Runtime ready: false" on a valid project.
+const FALLBACK_TRANSIENT_PATTERNS = [
+  /Navigating frame was detached/i,
+  /Target closed/i,
+  /Session closed/i,
+  /browser has disconnected/i,
+  /Page crashed/i,
+  /Execution context was destroyed/i,
+  /Cannot find context with specified id/i,
+  /Failed to launch the browser process/i,
+  /Navigation timeout of \d+ ms exceeded/i,
+  /ECONNREFUSED/i,
+  /net::ERR_NETWORK_CHANGED/i,
+  /Composition has zero duration[\s\S]*Runtime ready: false/,
+];
+
+/**
+ * Create + initialize a capture session with the canonical transient-init
+ * retry/cleanup the render pipeline uses (see probeStage in
+ * @hyperframes/producer): on a transient failure, close the crashed session
+ * and retry ONCE with a fresh browser. Without this, a standalone helper
+ * false-fails valid modular projects whose sub-composition timelines land a
+ * beat after the first readiness deadline ("zero duration" with
+ * "Runtime ready: false").
+ *
+ * `producer` is the imported @hyperframes/producer namespace;
+ * `createSession` is a factory returning a fresh (uninitialized) session.
+ * Non-transient init failures (e.g. the "Runtime ready: true" zero-duration
+ * fast-fail — a genuine authoring bug) still throw on the first attempt.
+ */
+export async function initializeSessionWithRetry(producer, createSession, options = {}) {
+  const maxAttempts = options.maxAttempts ?? 2;
+  const log = options.log ?? ((message) => console.error(message));
+  const isTransient =
+    typeof producer.isTransientBrowserError === "function"
+      ? producer.isTransientBrowserError
+      : (err) => {
+          const message = err instanceof Error ? err.message : String(err);
+          return FALLBACK_TRANSIENT_PATTERNS.some((pattern) => pattern.test(message));
+        };
+
+  for (let attempt = 1; ; attempt++) {
+    const session = await createSession();
+    try {
+      await producer.initializeSession(session);
+      return session;
+    } catch (error) {
+      await producer.closeCaptureSession(session).catch(() => {});
+      if (attempt >= maxAttempts || !isTransient(error)) throw error;
+      log(
+        `transient browser-init failure (attempt ${attempt}/${maxAttempts}): ${
+          error instanceof Error ? error.message : String(error)
+        }`,
+      );
+      log("retrying with a fresh browser session...");
+    }
+  }
+}
+
 export function hyperframesPackageSpec(packageName) {
   const override = process.env[VERSION_OVERRIDE_ENV]?.trim();
   if (override) return `${packageName}@${override}`;