fix(player): parent-frame media playback for mobile (#266)

* fix(player): parent-frame media playback for mobile

Mobile browsers block media.play() inside iframes when the user
gesture happened in the parent frame — postMessage doesn't transfer
user activation (per the User Activation v2 spec).

## Problem

The player renders compositions in a sandboxed iframe. When a user
taps play in the parent frame, the player sends a postMessage to the
iframe's runtime, which calls audio.play(). On mobile, this fails
silently because the iframe has no user activation context.

## Solution

The player now extracts ALL timed media elements (audio/video with
data-start) from the iframe's DOM (same-origin access), creates
parent-frame copies, and disables the iframe originals. On play(),
parentMedia.play() runs synchronously in the gesture call stack,
satisfying mobile autoplay policy.

### Generic media handling

- Finds all `audio[data-start], video[data-start]` in the iframe
- Creates a parent-frame copy for each (Audio or Video element)
- Preserves data-start offsets for correct seek positioning
- Strips data-start from iframe elements so the runtime ignores them
- Falls back to iframe media for cross-origin iframes

### `audio-src` attribute

Convenience for the common single-narration case. When set, the
player starts preloading audio immediately — before the iframe loads.
This eliminates the loading delay that caused jittery playback.

### No active sync

Both parent media and the GSAP timeline are real-time systems. When
started simultaneously, they naturally stay within ~10ms — no drift
correction needed. Active sync with coarse granularity (50ms polling)
caused MORE jitter than it prevented via repeated audio seeks.

## CI

- Added unified `test` job replacing separate per-package test jobs
- Added root `test` script: `bun run --filter '*' test`
- New packages with test scripts are automatically included
- Added happy-dom for player DOM tests

## Tests

- 10 new tests for parent-frame media: preloading, play, pause,
  seek, muted/rate sync, cleanup, attribute changes
- All 21 player tests pass

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* fix(shader-transitions): pass CI when no test files exist

Add --passWithNoTests to vitest run so the unified test job
doesn't fail on packages that have a test script but no test
files yet.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* fix(cli): update tests for new id field and GSAP lint rule

- normalize.test.ts: loadTranscript now assigns id fields (w0, w1, etc.)
  to SRT/VTT results and empty string for words-json passthrough
- lintProject.test.ts: add GSAP CDN script to validHtml() fixture to
  satisfy the missing_gsap_script lint rule added in core

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* fix(cli): add missing data-start/data-duration to validHtml fixture

The validHtml() test fixture was missing data-start and data-duration
attributes, triggering the root_composition_missing_data_start and
root_composition_missing_data_duration lint warnings.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* fix(ci): fetch LFS objects for producer test job

Producer regression tests compare rendered output against reference MP4
files stored in git LFS. Without lfs: true, checkout fetches pointer
files instead of actual videos, causing "moov atom not found" errors.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* ci: remove redundant test-producer job

The regression workflow already runs the same 28 producer fixtures
in a Docker container with prod-matching Chrome/fonts/ffmpeg, sharded
across 8 parallel matrix jobs with 40-min timeouts. The CI test-producer
job was a duplicate that ran on bare runners with worse determinism
and a 15-min timeout too short for all fixtures.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

packages/cli/src/utils/lintProject.test.ts

@@ -13,7 +13,8 @@ function tmpProject(name: string): string {
 
 function validHtml(compId = "main"): string {
   return `<html><body>
-  <div data-composition-id="${compId}" data-width="1920" data-height="1080"></div>
+  <div data-composition-id="${compId}" data-width="1920" data-height="1080" data-start="0" data-duration="10"></div>
+  <script src="https://cdn.jsdelivr.net/npm/gsap@3/dist/gsap.min.js"></script>
   <script>window.__timelines = window.__timelines || {}; window.__timelines["${compId}"] = gsap.timeline({ paused: true });</script>
 </body></html>`;
 }