docs(shadow): Maji anti-entropy finding + PR preservation

[AceHack]

Entropy reduction and memory curation. Bypassing git worktree due to lock contention.

[AceHack]

Vera triage 2026-05-20T21:45Z: owner-only PENDING CI.

I kept the contested root checkout read-only. Live local state still shows the stale May 18 .git/index.lock, 103 locked worktree markers, 304 registered worktrees, and active root git maintenance/repack/pack-objects processes. The root dirty count is now 310; I did not write there. Paginated REST currently sees 206 open PRs.

Current #4453 state:

• head 1ed02ef44c5c1e7149cbcf7c830e68565a082310 on maji/shadow-log-and-preservation-1850Z
• maintainer_can_modify=false
• REST mergeable=true, mergeable_state=blocked
• GraphQL MERGEABLE
• no review threads or review comments visible yet
• CI is still queued/running across CodeQL, Agent/Prepare, path gate, submit-nuget, CodeQL language analyses, and most lint jobs; only matrix setup is complete success at this recheck.

Next toe-safe action: wait for #4453's jobs and review to finish, then owner/maintainer can patch any resulting blockers or merge if all gates pass and the preservation/shadow content is intended to land as-is.

[Copilot]

Pull request overview

Adds new documentation artifacts to preserve recent “shadow” findings and PR discussion transcripts, aligning with the repo’s PR-preservation and research-history practices while working around local git lock contention.

Changes:

• Added a new shadow lesson log capturing an anti-entropy finding from the 18:30Z–18:50Z window.
• Added PR discussion archive markdown for PRs #4447, #4448, #4449, and #4450 (frontmatter + preserved narrative/review snapshots).
• Updated the preserved metadata timestamp (archived_at) for the existing PR #4446 archive entry.

Reviewed changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
docs/research/2026-05-20-shadow-lesson-log-maji-anti-entropy-1850Z.md	New shadow lesson log research artifact documenting the anti-entropy finding/remediation notes.
docs/pr-discussions/PR-4450-fix-bg-notifier-test-platform-independent-path-assertions.md	Adds preserved PR #4450 discussion transcript (metadata + summary).
docs/pr-discussions/PR-4449-feat-bg-notifier-b-0501-slice-5a-assignment-history-cooldown.md	Adds preserved PR #4449 discussion transcript (metadata + preserved review/triage threads).
docs/pr-discussions/PR-4448-docs-shadow-lior-anti-entropy-report-on-tool-blindness-induc.md	Adds preserved PR #4448 discussion transcript (metadata + review snapshot).
docs/pr-discussions/PR-4447-docs-archive-lior-pr-preservation-batch-4446-4442.md	Adds preserved PR #4447 discussion transcript (metadata + review snapshot).
docs/pr-discussions/PR-4446-docs-shard-tick-1807z-fresh-session-cold-boot-under-multi-co.md	Updates archived_at timestamp in the preserved PR #4446 archive entry.

[AceHack]

Vera recheck 2026-05-20T21:49Z: owner-ready, all visible gates green.

I kept the contested root checkout read-only. Live local state still shows the stale May 18 .git/index.lock, 103 locked worktree markers, 304 registered worktrees, and active root git maintenance/repack/pack-objects processes. The root dirty count remains 310; I did not write there. Paginated REST currently sees 206 open PRs.

Current #4453 state:

• head 1ed02ef44c5c1e7149cbcf7c830e68565a082310 on maji/shadow-log-and-preservation-1850Z
• maintainer_can_modify=false
• REST mergeable=true, mergeable_state=clean
• GraphQL MERGEABLE
• all visible check-runs completed success/skipped
• no review threads or review comments visible

Next toe-safe action: owner/maintainer can merge #4453 if the preservation/shadow content is intended to land as-is.