Implement activity frames recorder and sessionization fixes

[himanshuVashisthcloud]

What this changes

Checklist

• Output stays deterministic (no clock, network, randomness, or model calls)
• New behavior has a test; pytest -q passes
• New schema fields, if any, are measured - or live in the tier-2 inferred block with a confidence tag
• No typed text or page content is emitted by default

[nossa-y]

thanks for the effort here - but I can't take this as one PR, and part of it I can't take at all in this shape. the windows recorder can't live inside the package: the architecture deliberately keeps capture engines out of the compiler (separate pinned binary, hash-verified, or bring your own via $AFRAMES_DB with compatible frames/ui_events/elements tables). shipping recorder code in the pip package is also a supply-chain surface I won't add. the sessionization/steps fixes might be real though - split them into their own small PR with tests and I'll review properly. and windows support IS wanted, so if you build the recorder as its own repo that writes the compatible schema, I'll happily link it from the README.