docs: WhatStack launch film (landscape + vertical)

[kiro-agent]

Adds launch-video/: the 32s, 60fps launch film in 16:9 and 9:16, poster frames, GIF previews and the render source (Skia engine, beat timeline, capture script, generated score). Documentation only — not included in the store package (npm run pack ships only manifest, background, content, popup, shared and icons).

[xhawk-ai]

📋 Review Summary — Not ready to merge

2 medium findings would be worth fixing before merging.

Findings

1. Capture output is written where the engine never reads it ▶
2. The render scripts are CommonJS files inside an ESM package ▶

Fix with agent prompt

These are the findings from a code review of this pull request.

## 1. The render scripts are CommonJS files inside an ESM package
Path: launch-video/source/engine.js
Line: 4

Issue: The repository declares `"type": "module"` in `package.json`, so Node treats these `.js` files as ES modules. Running `node launch-video/source/render.js ...` aborts before rendering with `ReferenceError: require is not defined`; the same module-format mismatch exists in `render.js` and `stills.js`, so the added render/still source cannot be executed as written.
Suggested fix:
- Rename the CommonJS render files to `.cjs` and update their `require('./engine')` imports accordingly.
- Convert `engine.js`, `render.js`, and `stills.js` to ESM `import`/`export` syntax.

## 2. Capture output is written where the engine never reads it
Path: launch-video/source/capture.mjs
Line: 6

Issue: The capture script writes generated screenshots and `meta.json` under `/projects/sandbox/whatstack-video/cap/`, while the engine reads captures from `launch-video/source/cap/`. In a clean checkout the committed `cap/` directory only contains `meta.json`, so running capture and then render still leaves `page-*.jpg`, `pop-*.png`, `store.jpg`, and `src-stripe.html` missing from the path consumed by `E.load()`.
Suggested fix:
- Derive `OUT` from the checked-in source directory, for example `new URL('./cap/', import.meta.url)`, so captures are generated into the same directory that `engine.js` loads.

---

For each finding above, determine whether it is valid and should be fixed. If so, fix it directly. Where a finding offers several remedies, pick one and say why. Leave the pull request's own changed files alone unless a fix requires touching them.

Summary

The change adds a new launch-video/ documentation bundle with rendered launch-film assets and the code/timeline used to produce them. The packaged extension remains unaffected, but the checked-in render source is not reproducible in a clean checkout: the Node render scripts use CommonJS in an ESM package, and the capture script writes its generated assets to a different hard-coded sandbox path than the engine reads.

Commands

Re-review the latest changes:

@xhawk-ai review again

Resolve all review threads and post a summary:

@xhawk-ai resolve all

[xhawk-ai]

The render scripts are CommonJS files inside an ESM package

The repository declares "type": "module" in package.json, so Node treats these .js files as ES modules. Running node launch-video/source/render.js ... aborts before rendering with ReferenceError: require is not defined; the same module-format mismatch exists in render.js and stills.js, so the added render/still source cannot be executed as written.

Suggestions

• Rename the CommonJS render files to .cjs and update their require('./engine') imports accordingly.
• Convert engine.js, render.js, and stills.js to ESM import/export syntax.

[xhawk-ai]

Capture output is written where the engine never reads it

The capture script writes generated screenshots and meta.json under /projects/sandbox/whatstack-video/cap/, while the engine reads captures from launch-video/source/cap/. In a clean checkout the committed cap/ directory only contains meta.json, so running capture and then render still leaves page-*.jpg, pop-*.png, store.jpg, and src-stripe.html missing from the path consumed by E.load().

Suggestions

Derive OUT from the checked-in source directory, for example new URL('./cap/', import.meta.url), so captures are generated into the same directory that engine.js loads.