fix(web): clear persisted sim_id on reset (review round 2)

reset() now calls socket.clearSimId() so the next play() starts a fresh
simulation (CreateSimulation) instead of re-attaching to the old, reset
sim still alive within its TTL. Test asserts the post-reset play emits
CreateSimulation, not AttachSimulation.

Task: server-side-simulation review round 2, issue 001.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

.compozy/tasks/server-side-simulation/reviews-002/issue_001.md

@@ -3,7 +3,7 @@ provider: manual
 pr: 2
 round: 2
 round_created_at: 2026-07-05T15:16:15Z
-status: pending
+status: resolved
 file: apps/web/src/stores/simulationStore.ts
 line: 141
 severity: medium
@@ -46,5 +46,5 @@ Add a store test asserting that after `reset()` a subsequent `play()` emits
 
 ## Triage
 
-- Decision: `UNREVIEWED`
-- Notes:
+- Decision: `VALID`
+- Notes: Confirmed — `clearSimId()` was only called on the "unknown simulation" error, never on reset, so localStorage kept the id and the next play() re-attached to the old sim. Fixed: `reset()` now calls `socket.clearSimId()` before closing. Test added: "clears the persisted sim id so the next play starts a fresh simulation" asserts the next play() emits CreateSimulation, not AttachSimulation. Full suite green (248 web tests, turbo 7/7).

apps/web/src/stores/simulationStore.test.ts

@@ -202,4 +202,17 @@ describe('simulationStore — reset', () => {
     expect(store().simId).toBeNull()
     expect(store().scenarioVessels).toEqual([])
   })
+
+  it('clears the persisted sim id so the next play starts a fresh simulation', () => {
+    createSession()
+    expect(storage.getItem('ymir.simId')).toBe('sim-1')
+    store().reset()
+    expect(storage.getItem('ymir.simId')).toBeNull()
+
+    store().play(0.05)
+    lastWs().open()
+    const msgs = lastWs().sentMessages
+    expect(msgs.some((m) => m.type === 'CreateSimulation')).toBe(true)
+    expect(msgs.some((m) => m.type === 'AttachSimulation')).toBe(false)
+  })
 })

apps/web/src/stores/simulationStore.ts

@@ -141,6 +141,9 @@ export const useSimulationStore = create<SimulationStore>((set, get) => {
     reset() {
       const { socket, simId } = get()
       if (socket && simId) socket.send({ type: 'Reset', simId })
+      // Forget the persisted sim id so the next play() starts a fresh
+      // simulation instead of re-attaching to the old (reset) one.
+      socket?.clearSimId()
       socket?.close()
       pendingPlayDt = null
       set({ status: 'idle', error: null, state: null, connection: 'idle', socket: null, simId: null, scenarioVessels: [] })