fix(web): canonicalize fixture plan state

packages/client/connection/src/client/fixture.ts

@@ -510,7 +510,7 @@ export function createFixtureApi(): ApiProxy {
         if (planState?.pending !== undefined) {
           const active = planState.pending
           planStates.set(id, { active })
-          if (active !== planState.active) append(id, { type: 'plan/mode', data: { active } })
+          append(id, { type: 'plan/mode', data: { active } })
         }
         append(id, { type: 'user/message', surfaceOp: 'append', data: { content, source: { kind: 'user' } } })
         startReply(
@@ -551,10 +551,11 @@ export function createFixtureApi(): ApiProxy {
             details: { sessionId: request.payload.sessionId },
           })
         }
-        const target = state.pending ?? state.active
-        const next = request.payload.active === target
-          ? state
-          : { active: state.active, pending: request.payload.active }
+        const next = request.payload.active === state.active
+          ? { active: state.active }
+          : request.payload.active === state.pending
+            ? state
+            : { active: state.active, pending: request.payload.active }
         planStates.set(request.payload.sessionId, next)
         return ok(request, { ...next })
       },

packages/client/connection/tests/fixture.spec.ts

@@ -56,6 +56,9 @@ describe('createFixtureApi', () => {
     expect((await client.sessions.setPlanMode({ sessionId: sid('fx-alpha'), active: true })).result).toEqual({
       ok: true, value: { active: false, pending: true },
     })
+    expect((await client.sessions.setPlanMode({ sessionId: sid('fx-alpha'), active: true })).result).toEqual({
+      ok: true, value: { active: false, pending: true },
+    })
     expect((await client.sessions.cancel({ sessionId: sid('fx-alpha') })).result).toEqual({
       ok: true, value: { accepted: true },
     })
@@ -83,12 +86,12 @@ describe('createFixtureApi', () => {
     const createdId = created.result.value.sessionId
     await client.sessions.setPlanMode({ sessionId: createdId, active: true })
     expect((await client.sessions.setPlanMode({ sessionId: createdId, active: false })).result).toEqual({
-      ok: true, value: { active: false, pending: false },
+      ok: true, value: { active: false },
     })
-    // Selecting the effective target again is a no-op, and a net-zero pending
-    // target clears at the boundary without a redundant plan/mode event.
+    // Selecting the committed target clears pending immediately, and repeating
+    // that selection remains a no-op without a redundant plan/mode event.
     expect((await client.sessions.setPlanMode({ sessionId: createdId, active: false })).result).toEqual({
-      ok: true, value: { active: false, pending: false },
+      ok: true, value: { active: false },
     })
     await client.sessions.prompt({
       sessionId: createdId, mode: 'queue', content: [{ type: 'text', text: 'remain default' }],