Investigate rrweb integration for DOM snapshots at annotation timestamps

[BraedenBDev]

rrweb (https://github.com/rrweb-io/rrweb, MIT) is the industry standard for session replay, used by Sentry, PostHog, and DataDog. It records DOM mutations incrementally and can produce full snapshots at any point.

Value for PointDev:

• DOM snapshot at each annotation timestamp (supports Screenshot at each annotation timestamp #19)
• Console error capture via @rrweb/rrweb-plugin-console-record (supports M3)
• Session replay as a future output format for the bridge server (M6)

Blocker: rrweb inlines a base64-encoded Web Worker. Chrome Web Store rejects this as obfuscated code (rrweb issue #1699, open 2+ years). Options:

1. Fork and patch to load worker from separate file via chrome.runtime.getURL()
2. Use rrweb in sidepanel context and proxy events via messaging
3. Wait for upstream fix

Performance: ~29 KB gzipped (tree-shaken), +60 MB memory when enabled. Needs sampling config to be practical.

Action: Monitor upstream issue. If not resolved by M1, evaluate fork/patch effort.

See docs/design/library-research.md for full analysis.