Scaffold project and author 14-phase roadmap

Browser co-op kitchen game: FastAPI + native WebSockets, server-authoritative
20 Hz simulation, in-memory anonymous lobbies, data-driven YAML levels, Canvas 2D
vanilla ES-module client with locally authored SVG art and no external CDNs.

.agents/PLAN.md records the LOCKED decisions; .agents/user_stories/ holds the 12
flow contracts; .agents/phases/todo/ breaks them into 14 sequential, test-gated
phases (71 task files), each leaving the app launchable and the suite green.

LLM-Generated: true

.agents/user_stories/US-07_campaign_progression.md

@@ -0,0 +1,30 @@
+# US-07 — Progress through a campaign that gets harder
+
+**As a** player finishing level after level,
+**I want to** unlock the next kitchen and feel it get harder,
+**so that** a session has a trajectory instead of one repeated map.
+
+## Acceptance criteria
+1. The level list shows all shipped levels in campaign order with the difficulty pips,
+   target, time limit, and per-level best score/stars.
+2. Completing a level unlocks the next one **for that session**; the next level is
+   pre-selected in `ROUND_END` and startable by one action.
+3. Failing a level keeps the same next choice available (retry) and does not unlock
+   forward; unlocking never goes backwards.
+4. Level content comes from `levels/*.yaml`; adding a new valid YAML file makes the level
+   appear in `/api/levels` with no Python change (regression test).
+5. Every campaign level passes content validation: reachability, recipe solvability,
+   target plausibility, hazard references.
+6. Each consecutive level moves at least two escalation axes (§8 of PLAN.md) versus its
+   predecessor; the curve check fails the build otherwise.
+7. All 10 campaign levels are playable end to end with the intended station set.
+8. Progression state is per session token and survives a page reload; it is documented
+   as in-memory and lost on server restart.
+
+## E2E suite
+`tests/e2e/test_us07_campaign_progression.py` — win level 1, assert level 2 unlocked,
+selected, and startable; fail a level, assert locked. Plus
+`tests/unit/test_level_curve.py` for the escalation-axis and validation gates.
+
+## Phases
+`02_level_content_and_validation`, `11_campaign_levels_and_progression`