# Progress - explorer_m2_2

- Last visited: 2026-10-01T20:12:00Z
- Status: Investigation completed. Full technical report generated at `report.md` and 5-component handoff report generated at `handoff.md`. Ready for downstream Worker.
- Completed tasks:
  1. Computed exact coordinate space and pixel dimensions of 16x16 isometric chunks (TILE_W=64, TILE_H=32 -> 1024x512 px, 2.0 MiB per canvas).
  2. Designed LRU chunk cache pool (3-4 active OffscreenCanvas instances, RAM <= 8 MB, HTML5 canvas fallback, zero-allocation render loop).
  3. Designed reactive dirty-chunk invalidation mechanism matching `markChunkDirty(tx, ty)` called by `tile_grid_loader.js:setTileAt`.
  4. Defined camera pan eviction policy beyond 1-chunk visible border.
  5. Produced complete ~260 line reference implementation blueprint for `client/webapp/js/engine/tile_map_renderer.js`.
  6. Verified E2E test baseline (81/81 tests passed).
  7. Formulated verification commands and independent verification criteria.