framesieve 0.4.0: reference diff mode

[Jncch]

framesieve 0.4.0 - reference diff mode

Adds a third, opt-in diff mode so the gate can drop transient changes and only forward ones that stick.

What

• New diff.mode: "reference" (default stays "previous"): compares each frame against the last emitted frame instead of the previous one. A change that appears then reverts to that baseline before it persists is dropped (a hover tooltip that comes and goes); a change that stays for the new policy.referencePersistMs (default 3000) is emitted and becomes the new baseline (text typed, a panel that opens and stays).
• Detection is now two orthogonal axes, documented in the README: what to measure (diff.algorithm: downsample/pixel/edge) x what to compare against (diff.mode: previous/reference).
• A temporal filter, not a semantic one: whether a persistent change matters stays the caller's/VLM's job.

How

• Two-mask design: the adaptive weight is driven by frame-to-frame motion (BlockGrid.step takes score + motion masks; DiffEngine returns both), the gate by baseline divergence - so a held overlay keeps a high score and emits, while a chronically moving region is still down-weighted.
• diff.commit() advances the reference on emit (prime/threshold only, never keepalive), synchronously in recordEmit so an async transform cannot desync it.

Backward compatibility

• Default "previous" mode decides identically to 0.3.0: existing fixtures and examples/meeting/timeline.jsonl are byte-for-byte unchanged (goldens regenerate with no diff). New fixture tooltip-blip pins the transient-drop on real PNG frames.

Coordinated release

• core 0.4.0; adapters 0.3.0 and cli 0.2.0 bump their framesieve range to ^0.4.0 (no adapter/CLI code change); redact ranges bumped (still unpublished).

Verification

• npm run build && npm test && npm run lint && npm run smoke:pack all green (133 tests). Clean install resolves with no nested framesieve copies.

🤖 Generated with Claude Code

https://claude.ai/code/session_01WyitJEKkrbE4VYXnk2buwA