phase: 06_realtime_websocket_protocol

All green. Final verification complete — writing the report.

**Final pass report — phase 06 `realtime_websocket_protocol`**

- Verified: all 6 task files present in `complete/`; this was the final verification pass (no implementation work outstanding)
- `uv run ruff check .` → all checks passed; `uv run pyright` → 0 errors
- `uv run undercooked-levels validate` → content OK; `uv run pytest` (full suite) → **1751 passed, 0 failed, coverage 97.30% (>90% floor)**; slow sim stage (`-m slow tests/sim --no-cov`) → 2 passed; repo hygiene clean
- App launches: `/healthz` 200, `/` 200, `/api/levels`, `/api/config`, `POST /api/rooms` (201), `/api/stats` all verified live on an ephemeral port (server cleaned up)
- Criteria: scripted client room→hello→ready→start→countdown→≥20 snaps→round — PASS (`test_ws_round_two_clients.py`); identical `round` payloads both clients — PASS (`round_a == round_b`); version mismatch → `err protocol_mismatch` + close `4400` — PASS; 64 KB refused / 4 KB boundary, 500-burst → `rate_limited` → `4404` with bounded queue, 2000 malformed + 200 handshakes within memory bound — PASS; snap ≤ 1.5 KB (4p/4o/3h) and 64×64 ≤ 4 KB, downlink ≤ 60 KB/s over 100 ticks — PASS; `docs/PROTOCOL.md` model-sync test-enforced in both directions + full-round sequence diagram present — PASS
- Docs: README.md had 3 stale spots — status section (claimed 01–05 complete, 06 pending → now 01–06 complete, 07 pending), "until phases 06/07 wire the transport" wording, and the `PROTOCOL.md` layout note ("phase 06 completes it"). All fixed. AGENTS.md verified consistent — no changes needed
- No defects found in completed phases; no live infrastructure touched

Next pending phase: `07_canvas_client_and_hud`.

tests/fixtures/levels_playable/01_first_kitchen.yaml

@@ -0,0 +1,45 @@
+# levels/01_first_kitchen.yaml — campaign level 1, the tutorial kitchen.
+# Schema: docs/LEVELS.md · validated at startup and by `undercooked-levels
+# validate`. Every '#' is wall, every station stands on walkable floor.
+
+id: 01_first_kitchen
+name: First Kitchen
+order: 1
+difficulty: 1
+time_limit: 150
+target_score: 45
+blurb: >-
+  Your first shift: grab a tomato and an onion from the shelves, chop them,
+  cook the soup, plate it, and run it to the serve window before the clock
+  runs out. One dish, one of everything, nowhere to bump into each other.
+grid:
+  - "############"
+  - "#T..C...S..#"
+  - "#..........#"
+  - "#.P......X.#"
+  - "#..........#"
+  - "#..K....O..#"
+  - "#..........#"
+  - "#..........#"
+  - "############"
+tiles:
+  "#": {kind: wall}
+  ".": {kind: floor}
+  "T": {kind: floor, station: spawn_shelf, item: tomato}
+  "O": {kind: floor, station: spawn_shelf, item: onion}
+  "C": {kind: floor, station: chop_board}
+  "S": {kind: floor, station: stove}
+  "P": {kind: floor, station: prep}
+  "X": {kind: floor, station: serve}
+  "K": {kind: floor, station: sink}
+spawns: [[2, 7], [9, 7]]
+orders:
+  pool: [soup]
+  concurrent: 1
+  spawn_interval: [16, 20]
+  deadline: 60
+hazards: []
+escalation_notes: >-
+  Tutorial baseline (PLAN §8 campaign plan): one recipe, one order at a time,
+  slowest spawn interval, longest time budget, open floor, no hazards. Every
+  later level moves at least two axes up from these numbers.

tests/fixtures/levels_playable/recipes.yaml

@@ -0,0 +1,80 @@
+# levels/recipes.yaml — the campaign recipe book (PLAN §5/§8, A8).
+#
+# Every dish the game knows lives here; no Python enumerates recipes. The
+# schema is `src/undercooked/sim/recipe.py` and the reference is
+# docs/LEVELS.md — every model is strict (`extra="forbid"`), so a typo here
+# fails the load loudly instead of silently defaulting.
+#
+# Step lists mirror PLAN §5's station pipelines: pick from the spawn shelf,
+# chop (~0.9 s), cook on the stove, plate at the prep station, serve at the
+# window. `seconds` feeds only the validator's greedy target-plausibility
+# bound; the simulation (phase 04) re-enacts these steps per tick.
+
+# Catalog of the item kinds the campaign's dishes consume (documentation of
+# intent; spawn shelves are what actually put items on the floor).
+ingredients: [tomato, onion, lettuce, dough, patty, rice, fish, plate]
+
+recipes:
+  # tomato + onion -> chop -> pot on the stove -> plate
+  soup:
+    id: soup
+    name: Tomato Soup
+    base_score: 40
+    ingredients:
+      - {kind: tomato, form: raw}
+      - {kind: onion, form: raw}
+    steps:
+      - {kind: pick, station: spawn_shelf}
+      - {kind: chop, station: chop_board, seconds: 0.9}
+      - {kind: cook, station: stove, seconds: 5.0}
+      - {kind: plate, station: prep, seconds: 0.4}
+      - {kind: serve, station: serve}
+    tags: [hot, soup]
+
+  # lettuce + tomato -> chop -> plate; the fast, no-fire dish
+  salad:
+    id: salad
+    name: Garden Salad
+    base_score: 30
+    ingredients:
+      - {kind: lettuce, form: raw}
+      - {kind: tomato, form: raw}
+    steps:
+      - {kind: pick, station: spawn_shelf}
+      - {kind: chop, station: chop_board, seconds: 0.9}
+      - {kind: plate, station: prep, seconds: 0.4}
+      - {kind: serve, station: serve}
+    tags: [cold, quick]
+
+  # rice + onion straight onto the stove (PLAN §5: raw rice needs no board)
+  fried_rice:
+    id: fried_rice
+    name: Fried Rice
+    base_score: 50
+    ingredients:
+      - {kind: rice, form: raw}
+      - {kind: onion, form: raw}
+    steps:
+      - {kind: pick, station: spawn_shelf}
+      - {kind: cook, station: stove, seconds: 6.0}
+      - {kind: plate, station: prep, seconds: 0.4}
+      - {kind: serve, station: serve}
+    tags: [hot, grain]
+
+  # patty + dough + lettuce -> chop + pan on the stove -> plate. Defined now;
+  # later levels (phase 11) put it in an order pool.
+  burger:
+    id: burger
+    name: Chef's Burger
+    base_score: 70
+    ingredients:
+      - {kind: patty, form: raw}
+      - {kind: dough, form: raw}
+      - {kind: lettuce, form: raw}
+    steps:
+      - {kind: pick, station: spawn_shelf}
+      - {kind: chop, station: chop_board, seconds: 0.9}
+      - {kind: cook, station: stove, seconds: 5.0}
+      - {kind: plate, station: prep, seconds: 0.5}
+      - {kind: serve, station: serve}
+    tags: [hot, stacked]

tests/fixtures/levels_round/01_first_kitchen.yaml

@@ -0,0 +1,59 @@
+# tests/fixtures/levels_round/01_first_kitchen.yaml — the shipped campaign
+# level 1, verbatim in layout and content, with two numbers tuned for the
+# phase-06 two-client round suite (tests/integration/test_ws_round_two_clients.py).
+#
+# `target_score` is 20 (the shipped 45): one served soup scores 44-66
+# (`round(40 x 1.0 x 1.1 x (1 + 0.5 x fraction))` — sim/scoring.py), so the
+# first serve always crosses the target and the round ends `WON` on that
+# substep, whatever the wall-clock jitter of a live 20 Hz tick. The shipped
+# 150 s / 45 target would make a live-suite win depend on choreography timing
+# (a second serve within the 60 s order deadline); the wire contract the
+# suite locks (the round's events, payload and lobby return) is the same.
+#
+# `time_limit` is 60 s (the shipped 150): a safety margin around the ~25 s
+# scripted soup. If the choreography ever stalls, the round ends `LOST` at the
+# buzzer instead of running a two-and-a-half-minute test.
+#
+# Schema: docs/LEVELS.md — validated by the server's content gate at boot and
+# by `undercooked-levels validate` on a copy.
+
+id: 01_first_kitchen
+name: First Kitchen
+order: 1
+difficulty: 1
+time_limit: 60
+target_score: 20
+blurb: >-
+  Your first shift: grab a tomato and an onion from the shelves, chop them,
+  cook the soup, plate it, and run it to the serve window before the clock
+  runs out. One dish, one of everything, nowhere to bump into each other.
+grid:
+  - "############"
+  - "#T..C...S..#"
+  - "#..........#"
+  - "#.P......X.#"
+  - "#..........#"
+  - "#..K....O..#"
+  - "#..........#"
+  - "#..........#"
+  - "############"
+tiles:
+  "#": {kind: wall}
+  ".": {kind: floor}
+  "T": {kind: floor, station: spawn_shelf, item: tomato}
+  "O": {kind: floor, station: spawn_shelf, item: onion}
+  "C": {kind: floor, station: chop_board}
+  "S": {kind: floor, station: stove}
+  "P": {kind: floor, station: prep}
+  "X": {kind: floor, station: serve}
+  "K": {kind: floor, station: sink}
+spawns: [[2, 7], [9, 7]]
+orders:
+  pool: [soup]
+  concurrent: 1
+  spawn_interval: [16, 20]
+  deadline: 60
+hazards: []
+escalation_notes: >-
+  Integration-suite copy of the tutorial baseline (PLAN §8 campaign plan):
+  one recipe, one order at a time, open floor, no hazards.

tests/fixtures/levels_round/recipes.yaml

@@ -0,0 +1,80 @@
+# levels/recipes.yaml — the campaign recipe book (PLAN §5/§8, A8).
+#
+# Every dish the game knows lives here; no Python enumerates recipes. The
+# schema is `src/undercooked/sim/recipe.py` and the reference is
+# docs/LEVELS.md — every model is strict (`extra="forbid"`), so a typo here
+# fails the load loudly instead of silently defaulting.
+#
+# Step lists mirror PLAN §5's station pipelines: pick from the spawn shelf,
+# chop (~0.9 s), cook on the stove, plate at the prep station, serve at the
+# window. `seconds` feeds only the validator's greedy target-plausibility
+# bound; the simulation (phase 04) re-enacts these steps per tick.
+
+# Catalog of the item kinds the campaign's dishes consume (documentation of
+# intent; spawn shelves are what actually put items on the floor).
+ingredients: [tomato, onion, lettuce, dough, patty, rice, fish, plate]
+
+recipes:
+  # tomato + onion -> chop -> pot on the stove -> plate
+  soup:
+    id: soup
+    name: Tomato Soup
+    base_score: 40
+    ingredients:
+      - {kind: tomato, form: raw}
+      - {kind: onion, form: raw}
+    steps:
+      - {kind: pick, station: spawn_shelf}
+      - {kind: chop, station: chop_board, seconds: 0.9}
+      - {kind: cook, station: stove, seconds: 5.0}
+      - {kind: plate, station: prep, seconds: 0.4}
+      - {kind: serve, station: serve}
+    tags: [hot, soup]
+
+  # lettuce + tomato -> chop -> plate; the fast, no-fire dish
+  salad:
+    id: salad
+    name: Garden Salad
+    base_score: 30
+    ingredients:
+      - {kind: lettuce, form: raw}
+      - {kind: tomato, form: raw}
+    steps:
+      - {kind: pick, station: spawn_shelf}
+      - {kind: chop, station: chop_board, seconds: 0.9}
+      - {kind: plate, station: prep, seconds: 0.4}
+      - {kind: serve, station: serve}
+    tags: [cold, quick]
+
+  # rice + onion straight onto the stove (PLAN §5: raw rice needs no board)
+  fried_rice:
+    id: fried_rice
+    name: Fried Rice
+    base_score: 50
+    ingredients:
+      - {kind: rice, form: raw}
+      - {kind: onion, form: raw}
+    steps:
+      - {kind: pick, station: spawn_shelf}
+      - {kind: cook, station: stove, seconds: 6.0}
+      - {kind: plate, station: prep, seconds: 0.4}
+      - {kind: serve, station: serve}
+    tags: [hot, grain]
+
+  # patty + dough + lettuce -> chop + pan on the stove -> plate. Defined now;
+  # later levels (phase 11) put it in an order pool.
+  burger:
+    id: burger
+    name: Chef's Burger
+    base_score: 70
+    ingredients:
+      - {kind: patty, form: raw}
+      - {kind: dough, form: raw}
+      - {kind: lettuce, form: raw}
+    steps:
+      - {kind: pick, station: spawn_shelf}
+      - {kind: chop, station: chop_board, seconds: 0.9}
+      - {kind: cook, station: stove, seconds: 5.0}
+      - {kind: plate, station: prep, seconds: 0.5}
+      - {kind: serve, station: serve}
+    tags: [hot, stacked]