feat: Streaming Diff Oven (agent-agnostic, ported onto main)

[apresmoi]

Builds on @alowpoly's #5 and the design we worked out in that thread. Ports the Streaming Diff Oven onto current main and makes capture agent-agnostic (Codex + Claude Code). Opened as a separate PR only because #5's branch is far behind on the old layout; co-authored with @alowpoly.

What it does

Watch an agent edit your repo, live. Hooks bracket each file-mutating tool call and publish a timestamped, per-session diff feed into git-ignored .local/; the dashboard streams it over SSE.

agent edit -> pre/post hook -> burnlist streaming-diff capture -> .local feed -> dashboard (SSE)

Key decisions

• No tokens: the CLI writes .local/ atomically; the dashboard is a read-only observer.
• Pre-to-post snapshot diff (not git diff HEAD), so pre-existing dirty changes are never misattributed to the tool.
• Honesty is structural: opaque / denied / redacted / truncated / overlapping edits render partial, never a false captured.
• Deny-by-default content policy: secrets, .env, ignored, .git/, and symlink escapes are never captured; secret patterns are redacted before any write.
• Kept lean: role/task roster deferred, Visual Parity stays its own oven, watch dropped.

Install

burnlist hooks install --agent codex,claude merges hooks into .codex/hooks.json + .claude/settings.json (agent-specific events, capability check, all-or-nothing).

Verification

npm run verify is green (414 tests) on Node 18/20/22, including HTTP/SSE integration and a socketless synthetic acceptance test. The repo-state cross-process lock was also redesigned into a directory-lock primitive to close crash-recovery races and de-flake Node 18 CI.

Please poke holes, especially at: pre-to-post attribution, the read-only-observer boundary, the content/redaction policy, and the Codex/Claude adapter payload mapping.