fix(web): fence request telemetry lifecycles

packages/client/runtime/tests/client-apply.spec.ts

@@ -118,7 +118,7 @@ describe('runtime client apply', () => {
         type: 'session/model-request',
         sessionId: 's-state',
         turn: 1,
-        step: 0,
+        step: 1,
         provider: 'test',
         model: 'alpha',
         contextTokens: 32_000,
@@ -145,7 +145,7 @@ describe('runtime client apply', () => {
         type: 'session/model-request',
         sessionId: 's-state',
         turn: 2,
-        step: 0,
+        step: 1,
         provider: 'test',
         model: 'beta',
         contextTokens: 48_000,

packages/client/runtime/tests/manager.spec.ts

@@ -156,6 +156,19 @@ describe('instances', () => {
       payload: { type: 'host/session-removed', sessionId: S1 },
     })
     expect(session.getSnapshot().modelRequest).toBeNull()
+    manager.handleMuxEnvelope({
+      rpcId: 'late-resident-request' as never,
+      payload: {
+        type: 'session/model-request',
+        sessionId: S1,
+        turn: 2,
+        step: 1,
+        provider: 'test',
+        model: 'late',
+        contextWindow: 512_000,
+      },
+    })
+    expect(session.getSnapshot().modelRequest).toBeNull()
 
     manager.handleMuxEnvelope({
       rpcId: 'request-before-lazy-removal' as never,
@@ -173,6 +186,18 @@ describe('instances', () => {
       rpcId: 'lazy-removed' as never,
       payload: { type: 'host/session-removed', sessionId: S2 },
     })
+    manager.handleMuxEnvelope({
+      rpcId: 'late-lazy-request' as never,
+      payload: {
+        type: 'session/model-request',
+        sessionId: S2,
+        turn: 2,
+        step: 1,
+        provider: 'test',
+        model: 'late-lazy',
+        contextWindow: 512_000,
+      },
+    })
     expect(manager.get(S2).getSnapshot().modelRequest).toBeNull()
   })
 

packages/client/runtime/tests/session.spec.ts

@@ -822,6 +822,33 @@ describe('remaining branches', () => {
 })
 
 describe('resync', () => {
+  it('settles an in-flight open when its connection generation dies', async () => {
+    const { api, session } = makeSession()
+    const stale = deferred<Awaited<ReturnType<FakeApiClient['onHistory']>>>()
+    api.onHistory = () => stale.promise
+    const opening = session.open()
+    expect(session.getSnapshot().openState).toBe('loading')
+
+    session.handleReconnecting()
+    expect(session.getSnapshot()).toMatchObject({
+      openState: 'error',
+      openError: {
+        code: 'internal',
+        message: 'connection lost while loading session history',
+      },
+    })
+
+    stale.reject(new Error('dead generation failed'))
+    await opening
+    expect(session.getSnapshot()).toMatchObject({
+      openState: 'error',
+      openError: {
+        code: 'internal',
+        message: 'connection lost while loading session history',
+      },
+    })
+  })
+
   it('clears request telemetry on reconnect and drops a stale in-flight history response', async () => {
     const { api, session } = makeSession()
     const stale = deferred<Awaited<ReturnType<FakeApiClient['onHistory']>>>()