## 1. Implementation
- [x] Add an in-memory summary-agent write audit component.
- [x] Capture project-file and dictation-dictionary diffs while excluding summary and assistant-context writes.
- [x] Append the collected audit to assistant context after the summary agent finishes.

## 2. Verification
- [x] Add behavior tests for project-file diff capture, dictionary diff capture, and summary/context exclusion.
- [x] Run focused summary/project tool tests.
- [x] Run `openspec validate add-summary-agent-write-diff-audit --strict`.