phase: 07_canvas_client_and_hud

**Final report — phase 07 final verification pass**

- **Verified:** all 5 tasks present in `complete/`; app boots (`/healthz` 200, `/` 200, static + atlas + `/api/levels` served); `docs/CLIENT.md` module map matches the on-disk `app/static/` tree; no code defects found.
- **Tests/lint/coverage:** `bash .agents/validate.sh` → ruff clean, pyright 0 errors, `undercooked-levels validate` pass, **full pytest 1838 passed, 97.21% coverage (floor 90%)**, slow sim stage 2 passed, repo hygiene clean. `uv run pytest tests/e2e -q` → **53 passed** (all 8 suites added this phase).
- **Criteria:** (1) two tabs create→join→ready→start→serve one dish, keyboard only — green via `test_us01/02/03/04` ✔; (2) e2e green ✔; (3) canvas non-blank, pixels change after a move — `test_us04_render_smoke` ✔; (4) HUD score within 200 ms of the `served` event — asserted, green ✔; (5) zero console errors + zero off-origin requests — `test_atlas_loads` / `test_us01_landing_surface` ✔; (6) `docs/CLIENT.md` matches layout ✔; (7) 100% suite + 97.21% ✔; (8) docs pass below ✔; (9) no regression in completed phases (all prior suites green) ✔.
- **README.md fixed:** status still said "next pending phase is 07" → now 07 complete, 08 pending; the phase-07 client text buried in the phase-05 bullet → its own "canvas client, art, HUD (phase 07)" bullet; stale "What does not exist yet" (claimed movement/controls missing) → rewritten to phases 08–14; "once the room flow ships" → "live in the browser today"; Layout `app/static/` "renderer arrives with the rest of phase 07" → full shipped-client map; Layout `docs/` "CLIENT lands with phase 07" → `CLIENT.md` listed; added `gen_art_index.py` Layout entry.
- **AGENTS.md fixed:** "the eight screens" (7 listed) → "the seven screens" (+ `dom.js` is the shared builder, not a screen); e2e naming line → notes the non-story guard `test_atlas_loads.py`.
- **Decisions:** no code changes were needed; only the two doc fixes above. Docs re-verified by `test_docs_commands`/`test_docs_index` (44 passed) plus the final full gate.
- **Next pending phase:** `08_client_prediction_and_touch`.

tests/integration/test_ws_handshake.py

@@ -195,6 +195,37 @@ async def test_happy_handshake_welcome_and_lobby(ws_server: Any) -> None:
             assert len(lobby2["seats"]) == 2
 
 
+async def test_a_new_seat_rebroadcasts_the_lobby_to_existing_members(
+    ws_server: Any,
+) -> None:
+    """PLAN §7: the lobby is re-broadcast on lobby-state changes, not
+    only to the joiner — a member who is already in the room must see
+    the new seat appear (and a ghost rejoin revives it), so the lobby
+    screen in an open tab updates without a refresh."""
+    with ws_server() as (url, _app):
+        code, _ = _create_room(url, "tok-host")
+        async with await _connect(url, code, "tok-host", name="Host") as host:
+            welcome = await _next_json(host)
+            assert welcome["type"] == "welcome"
+            await _next_json(host)  # the initial lobby (one seat)
+            # The joiner arrives on their own socket: welcome + lobby for
+            # them, and a *re-broadcast* for the host.
+            async with await _connect(
+                url, code, "tok-joiner", name="Joiner"
+            ) as joiner:
+                j_welcome = await _next_json(joiner)
+                assert j_welcome["type"] == "welcome"
+                assert j_welcome["you"]["seat"] == 1
+                j_lobby = await _next_json(joiner)
+                assert j_lobby["type"] == "lobby"
+                host_lobby = await _next_json(host)
+                assert host_lobby["type"] == "lobby"
+                assert host_lobby["code"] == code
+                assert len(host_lobby["seats"]) == 2
+                assert host_lobby["seats"][1]["name"] == "Joiner"
+                assert host_lobby["seats"][1]["ready"] is False
+
+
 async def test_ping_before_hello_gets_pong(ws_server: Any) -> None:
     with ws_server() as (url, _app):
         code, _ = _create_room(url)