---
phase: 06.3
plan: "01"
subsystem: diagnostics
tags: [server, client, room-layout, collision, telemetry]
requires:
  - phase: "06.2"
    provides: "Initial room_layout delivery and RoomRenderer staging telemetry"
provides:
  - "Server pino d40_layout_broadcast payload trace on per-client room_layout delivery"
  - "Client window.__rebno walkable grid and collision payload diagnostics"
affects: [phase-06.3, D-40, D-54, RoomRenderer, RebnoRoom]
tech-stack:
  added: []
  patterns: ["Unconditional staging-visible window.__rebno diagnostic publish"]
key-files:
  created: []
  modified:
    - apps/server/src/RebnoRoom.ts
    - apps/client/src/render/RoomRenderer.ts
key-decisions:
  - "Used the existing module pino logger `log` because RebnoRoom has no instance `this.logger`."
patterns-established:
  - "Room layout diagnostics should capture both server payload shape and client-derived grid counts."
requirements-completed:
  - REQ-CLI-06
  - REQ-CLI-08
duration: 14 min
completed: 2026-05-14
---

# Phase 06.3 Plan 01: D-40/D-54 Layout Telemetry Summary

**Room layout delivery now emits server payload traces and client walkable-grid diagnostics for D-40/D-54 root-cause confirmation**

## Performance

- **Duration:** 14 min
- **Started:** 2026-05-14T08:47:00Z
- **Completed:** 2026-05-14T09:01:00Z
- **Tasks:** 3
- **Files modified:** 2

## Accomplishments

- Added `d40_layout_broadcast` pino log fields before per-client `room_layout` send.
- Added `window.__rebno.walkableCellsTrue`, `walkableCellsTotal`, `tilesOOB`, `payloadHasCollisionPolys`, and `payloadWallBorder`.
- Kept the spike behavior-only: no protocol version bump and no wire payload mutation.

## Task Commits

1. **Task 1/2/3: Server and client D-40/D-54 telemetry** - `1bbf3fa` (`spike(06.3-01)`)

## Files Created/Modified

- `apps/server/src/RebnoRoom.ts` - Added per-client layout payload trace using the loaded canonical layout object.
- `apps/client/src/render/RoomRenderer.ts` - Extended unconditional staging telemetry with grid and collision payload fields.

## Decisions Made

- Used `log.info(...)` instead of `this.logger.info(...)`; `RebnoRoom` currently imports and uses the module pino logger and has no instance logger.

## Deviations from Plan

### Auto-fixed Issues

**1. [Rule 3 - Blocking] Used existing module logger instead of nonexistent `this.logger`**
- **Found during:** Task 1 read-first inspection.
- **Issue:** Plan assumed `this.logger.info(...)` existed, but `RebnoRoom` uses imported `log`.
- **Fix:** Logged the same payload through `log.info(...)`, preserving pino structured logging semantics.
- **Files modified:** `apps/server/src/RebnoRoom.ts`
- **Verification:** Server tests passed.
- **Committed in:** `1bbf3fa`

---

**Total deviations:** 1 auto-fixed (1 blocking codebase-shape mismatch).
**Impact on plan:** No behavior or observability reduction; the event fields and message match the plan.

## Issues Encountered

None beyond the logger-shape deviation.

## Verification

- `pnpm --filter @rebno/server test --run` - PASS, 11 test files passed, 61 tests passed.
- `pnpm --filter @rebno/client test --run` - PASS, 26 test files passed, 190 tests passed, 4 todo.
- Acceptance grep confirmed all required telemetry fields are present.

## User Setup Required

None - no external service configuration required.

## Next Phase Readiness

Ready for `06.3-09` NAVI_MASK correction and `06.3-10` D-40 residual payload/render fix. Operator still needs staging logs/devtools values to confirm the expected mvp-room field values.

---
*Phase: 06.3*
*Completed: 2026-05-14*