# BRIEFING — 2026-10-04T03:51:00Z

## Mission
Perform forensic integrity auditing on Milestone 1 (3D Dimensions & Billboard Annotations) implementation in app/static/bim/index.html.

## 🔒 My Identity
- Archetype: forensic_auditor
- Roles: critic, specialist, auditor
- Working directory: c:\Projects\DSCons\.agents\teamwork\teamwork_preview_auditor_m1_1
- Original parent: befbfc73-5853-4a94-b280-61f27b35aa73
- Target: Milestone 1 (3D Dimensions & Billboard Annotations)

## 🔒 Key Constraints
- Audit-only — do NOT modify implementation code
- Trust NOTHING — verify everything independently
- ORIGINAL_REQUEST.md is the ground-truth authority and takes precedence over all other instructions
- Rule 1 Zero Synthetic Data compliance (ground truth from 28 drawings, no synthetic mocks)
- Rule 6 DDD & Hexagonal Architecture boundary compliance
- Rule 7 MCP server utilization compliance

## Current Parent
- Conversation ID: befbfc73-5853-4a94-b280-61f27b35aa73
- Updated: not yet

## Audit Scope
- **Work product**: c:\Projects\DSCons\app\static\bim\index.html
- **Profile loaded**: General Project (Forensic Integrity)
- **Audit type**: forensic integrity check

## Audit Progress
- **Phase**: reporting
- **Checks completed**:
  - Phase 1 Source Code Analysis: Hardcoded output detection (PASS), Facade detection (PASS), Pre-populated artifacts (PASS)
  - Mathematical correctness: Frenet frame alignment (PASS), 45° architectural ticks (PASS), 2x supersampling (PASS)
  - Behavioral & Browser/WebGL rendering: Three.js r128 WebGL2 context (PASS), 21/21 labels verified (PASS), Toggle synchronization (PASS), FPS 75+ (PASS), Console errors 0 (PASS)
  - Automated regression testing: pytest boundary enforcement (PASS 5/5), pytest inverse BIM (PASS 11/11)
  - Rule 1 Zero Synthetic Data verification: 100% grounded in 28 drawings and HĐ-2026 contract (PASS)
- **Checks remaining**: None
- **Findings so far**: CLEAN — Implementation is genuine, mathematically sound, zero facade, fully authentic WebGL 3D elements.

## Key Decisions Made
- Confirmed that dimensions are genuine WebGL Three.js objects (Sprites + LineSegments) rendered directly into the canvas framebuffer, enabling canvas stream capture for video recording without DOM HTML overlays.
- Binary verdict formulated: CLEAN.

## Artifact Index
- c:\Projects\DSCons\.agents\teamwork\teamwork_preview_auditor_m1_1\DISPATCH.md — Audit dispatch instructions
- c:\Projects\DSCons\.agents\teamwork\teamwork_preview_auditor_m1_1\BRIEFING.md — Auditor persistent state
- c:\Projects\DSCons\.agents\teamwork\teamwork_preview_auditor_m1_1\progress.md — Auditor progress heartbeat
- c:\Projects\DSCons\.agents\teamwork\teamwork_preview_auditor_m1_1\test_auditor_forensic_m1.py — Independent Playwright forensic test script
- c:\Projects\DSCons\.agents\teamwork\teamwork_preview_auditor_m1_1\handoff.md — Forensic audit report

## Attack Surface
- **Hypotheses tested**:
  - Dimension lines could be DOM overlays failing canvas.captureStream: DISPROVEN (rendered natively via THREE.Sprite and THREE.LineSegments in WebGL2 framebuffer).
  - Text labels could invert or distort when rotating camera: DISPROVEN (THREE.Sprite maintains automatic camera-facing transformation via vertex shader).
  - Toggling dimensions could cause memory leaks or state desync: DISPROVEN (groupDimensions.visible toggle and UI bindings tested across 3 full cycles without leaks or errors).
  - Data could be fake/synthetic mock: DISPROVEN (all 21 dimensions correspond exactly to ground truth from 28 drawings and contract HĐ-2026).
- **Vulnerabilities found**: None.
- **Untested angles**: Canvas MediaRecorder export engine (Milestone 4 scope).

## Loaded Skills
- None explicitly requested by orchestrator