# Review by Principal Systems Engineer (Google/Stripe caliber) (Round 1)

## Review Complete — Principal Systems Engineer

**VERDICT: approve**

**FINDINGS:**
- [src/colonyos/tui/widgets/transcript.py]: `_unread_lines` counter increments once per `_scroll_to_end` call regardless of actual line count — acceptable since count is internal-only and notification text is generic
- [src/colonyos/tui/widgets/transcript.py]: No test asserts `self.notify()` is actually called — reasonable tradeoff, state machine behavior is tested
- [tests/tui/test_transcript.py]: `test_unread_lines_resets_when_auto_scroll_reengages` manually sets state rather than triggering through `on_scroll_y` — slightly weaker than testing the real path, but functionally equivalent
- [src/colonyos/tui/styles.py]: The `overflow: hidden` on Screen is broad — if future widgets need Screen-level scrolling, this will need revisiting. Correct for current architecture.

**SYNTHESIS:**
This is a clean, well-scoped bugfix that addresses all three root causes identified in the PRD. The implementation is surgical — 53 lines of production code across 3 files, with 310 lines of tests. All architectural decisions are correct: disabling RichLog's built-in `auto_scroll` eliminates the dual-controller fight, the CSS inheritance-vs-containment fix is textbook, and `_pending_programmatic_clear` solves the async timing race without framework timing dependencies. The notification strategy (`self.notify()` with a 0→1 transition guard) is the simplest thing that works. No new dependencies, no framework fights, no over-engineering. All 3,074 tests pass with zero regressions. Ship it.
