# Progress — explorer_m3_1

Last visited: 2026-10-01T21:15:00Z
Status: Complete

## Completed Steps
- [x] Initialized DISPATCH.md with incoming timestamp header (2026-10-01T20:54:28Z)
- [x] Updated BRIEFING.md with append-only preservation of locked identity and constraints
- [x] Inspected `client/webapp/js/engine/collision_engine.js` (218 lines, existing boundary clamp, prop footprints, sliding)
- [x] Inspected `client/webapp/js/engine/tile_grid_loader.js`, `tile_map_renderer.js`, and `canvas_renderer.js`
- [x] Analyzed canonical TileType schema in `server/world/map_data_types.py` (20 codes: VOID=0, FLOOR=1, WALL=2, CHASM=9, BOSS_GATE=10, WATER=19)
- [x] Reconciled discrepancy between dispatch prompt tile numbers `(WALL=1, CHASM=4, WATER=5, BOSS_GATE=15)` and canonical schema `(WALL=2, CHASM=9, WATER=19, BOSS_GATE=10)`
- [x] Evaluated player radius multi-sample edge testing (4-8 radial points) vs Circle-AABB clamping ($tx_{\min}..tx_{\max} \le 4$ tiles)
- [x] Formulated zero-allocation 2-axis sliding physics (`SLIDE_RESULT` reuse)
- [x] Formulated dodge/blink chasm bypass logic and endpoint safety checks (`canBypassChasm`)
- [x] Formulated boss gate integration (`bossGateBreached` / `setTileAt(gx, gy, 1)`)
- [x] Formulated exact code structure for `collision_engine.js` staying well within <= 320 lines (estimated 255 lines)
- [x] Wrote `report.md` with in-depth analysis, mathematical formulas, and benchmarks
- [x] Wrote `handoff.md` with self-contained 5-component structure
- [x] Verified existing test suites pass cleanly (81 passing pytest items in `test_poe2_map_system_e2e.py`)
- [x] Verified hygiene audit passes cleanly with 0 hard cap violations
- [x] Notified parent orchestrator via send_message