# BRIEFING — 2026-10-04T04:20:00Z

## Mission
Adversarially verify the Site Diary Dock, layout boundaries, Zero Occlusion, and mobile resize guard for Milestone 2.

## 🔒 My Identity
- Archetype: EMPIRICAL CHALLENGER
- Roles: critic, specialist
- Working directory: c:\Projects\DSCons\.agents\teamwork\teamwork_preview_challenger_m2_2
- Original parent: befbfc73-5853-4a94-b280-61f27b35aa73
- Milestone: Milestone 2 (4D BIM Simulation & Interactive Site Diary Dock)
- Instance: 2 of 2

## 🔒 Key Constraints
- Review-only — do NOT modify implementation code (report findings/verdict)
- Zero mock synthetic data (rule from AGENTS.md)
- Real browser empirical testing required (Playwright / Chrome DevTools)
- Do not place source code, tests, or data files in .agents/teamwork/ (only metadata)
- Empirical challenger mandate: MUST run verification code yourself, do NOT trust claims or logs, if you cannot reproduce a bug empirically it does not count.

## Current Parent
- Conversation ID: befbfc73-5853-4a94-b280-61f27b35aa73
- Updated: 2026-10-04T04:20:00Z

## Review Scope
- **Files to review**: c:\Projects\DSCons\app\static\bim\index.html
- **Interface contracts**: c:\Projects\DSCons\.agents\teamwork\ORIGINAL_REQUEST.md, c:\Projects\DSCons\.agents\teamwork\teamwork_preview_orchestrator_1\PROJECT.md
- **Review criteria**: Dock 50 toggles (195px / 32px), Zero Occlusion (dockRect.right <= sidebarRect.left), mobile resize guard (camera.aspect not NaN/Infinity), Check 5 & Check 6 Playwright tests.

## Attack Surface
- **Hypotheses tested**:
  - H1: Dock height fails to toggle cleanly between 195px and 32px or suffers layout flickering/CLS across 50 toggles. [DISPROVED - 100% passed]
  - H2: Site Diary dock overlaps right sidebar (violating Zero Occlusion rule). [DISPROVED - 100% passed]
  - H3: Resizing to mobile viewport (375x667) causes container clientWidth = 0, producing NaN or Infinity in camera.aspect. [DISPROVED - 100% passed, safeguard active]
  - H4: Scrubbing timeline while collapsed fails to update DOM or drops data upon expansion. [DISPROVED - 100% passed]
- **Vulnerabilities found**: None. System is resilient against stress testing.
- **Untested angles**: Milestone 3 Canvas MediaRecorder 1080p video export sweep.

## Loaded Skills
- **Source**: c:\Projects\DSCons\.agents\skills\enterprise-ui-darkslate\SKILL.md
- **Local copy**: N/A (read directly)
- **Core methodology**: Dark Slate theme, high density, Zero Occlusion against sidebar, Toast anti-flood.

## Key Decisions Made
- Executed 14-check adversarial stress test harness (`tools/verification/test_adversarial_m2_dock_and_resize.py`).
- Executed Check 5 & Check 6 Playwright suite and backend regression suite (all 100% passed).
- Formulated verdict: APPROVE.

## Artifact Index
- `DISPATCH.md` — Inbound instructions
- `BRIEFING.md` — Persistent awareness
- `progress.md` — Execution tracking
- `tools/verification/test_adversarial_m2_dock_and_resize.py` — Adversarial test harness
- `reports/stress_m2/` — Generated verification screenshots
- `handoff.md` — 5-component handoff report