[4/7] feat: explain session activity, usage and attention

[BIackFIame]

Summary

Part 4/7 of the CanvasTTY agent-workflow series. Durable timelines, session reports and searchable output history explain long-running work. Missing usage remains unknown; loop-detection hooks and attention events expose stalled work. Output history includes streaming secret redaction and masked worker snapshots.

Review scope and dependencies

Depends on: #133.

This is a cumulative upstream PR: GitHub's Files changed tab includes earlier unmerged parts because all PRs target upstream main; cross-fork stacked bases are unsupported. Review this part in the isolated predecessor-to-head diff. The intended merge order follows the numbered series; do not merge a later part independently of its predecessors.

The Assistant plugin supplies loop judgments. Phone transport is in the final experimental part.

Validation and current blockers

Tested feature head: 21d5c99f7957ec98ea5aa893127ec6360b6084fe. Local helpers, typecheck, build and secret audit passed; full suite: 1,968 passed, 8 skipped, zero failures. Historical fork CI passed on macOS, Linux and Windows using the exact candidate tree under a temporary workflow overlay. That overlay is not included here.

Draft: merge preview against updated upstream 6faadcdc found conflicts in src/preload/index.ts, src/renderer/src/features/workspace/WorkspaceCanvas.tsx, src/shared/contracts.ts. These historical results do not validate a conflict-resolved integration with current main. Preserve the newly accepted material/terminal-link behavior, resolve the overlaps, and rerun checks before marking ready.

Historical hidden-app evidence recorded timeline events and notification payloads; actual OS/phone delivery was not exercised. A deterministic loop fixture triggered after six denied actions, without model calls. Real-model loop detection and large-history performance remain unverified.

Series order

1. macOS clipboard
2. Orchestration, reviews and budgets — Draft
3. Worktrees and checkpoints — Draft
4. Timeline, usage and attention — Draft
5. Network policies and temporary secrets — Draft
6. Workspace context and navigation — Draft
7. Experimental routing, handoff and remote controls — Draft

Parts 2–7 are cumulative Draft PRs against upstream main, with an isolated layer diff in each description. Their tested feature heads currently conflict with newer upstream changes; integration and fresh checks are required before readiness. Part 7 also retains its independent experimental acceptance gate.

[BIackFIame]

@codex review

Please review this PR for correctness, regressions and security issues. Review only; post findings on GitHub without changing code.

This is part 4/7 of a cumulative series. Focus on changes introduced after predecessor 2b988218680596776177862ef2fb53daa5549c6b through current head 21d5c99f7957ec98ea5aa893127ec6360b6084fe, including their interactions with the inherited code. The isolated layer diff is linked in the PR description. Known merge conflicts with newer main are already documented; look for substantive code defects in addition to those integration blockers.