fix(claude): block replay fallback after waiter eviction

src/main/claude/claude-structured-dispatch.test.ts

@@ -17,6 +17,7 @@ function sessionFor(send = vi.fn().mockResolvedValue(undefined)): ClaudeSession
     prompts: {} as ClaudeSession['prompts'],
     dispatchWaiters: [],
     retiredDispatchWaiters: [],
+    replayContentFallbackBlocked: false,
     dispatchSequence: 0,
     optionMutationSequence: 0,
     options: new Map(),
@@ -111,6 +112,59 @@ describe('Claude structured dispatch image limits', () => {
     await expect(second).resolves.toMatchObject({ providerIdentity: { uuid: secondUuid } })
   })
 
+  it('does not let a fresh-UUID replay for an evicted dispatch resolve active dispatch B', async () => {
+    const session = sessionFor()
+    const first = dispatchClaudeTurn(
+      session,
+      { clientMessageId: 'client-1', body: userMessage([{ type: 'text', text: 'same prompt' }]) },
+      100
+    )
+    await vi.waitFor(() => expect(session.dispatchWaiters).toHaveLength(1))
+    await expect(first).resolves.toMatchObject({ state: 'unknown' })
+    const firstUuid = session.retiredDispatchWaiters[0]!.sentUuid
+
+    const fillerDispatches = await Promise.all(
+      Array.from({ length: 64 }, (_, index) =>
+        dispatchClaudeTurn(
+          session,
+          {
+            clientMessageId: `filler-${index}`,
+            body: userMessage([{ type: 'text', text: 'same prompt' }])
+          },
+          5
+        )
+      )
+    )
+    expect(fillerDispatches.every((outcome) => outcome.state === 'unknown')).toBe(true)
+    expect(session.retiredDispatchWaiters).toHaveLength(64)
+    expect(session.replayContentFallbackBlocked).toBe(true)
+    expect(session.retiredDispatchWaiters.some((waiter) => waiter.sentUuid === firstUuid)).toBe(
+      false
+    )
+
+    while (session.retiredDispatchWaiters.length > 0) {
+      const sentUuid = session.retiredDispatchWaiters[0]!.sentUuid
+      resolveClaudeReplayWaiter(session, userReplayFrame(sentUuid, 'same prompt'))
+    }
+    expect(session.retiredDispatchWaiters).toHaveLength(0)
+
+    const second = dispatchClaudeTurn(
+      session,
+      { clientMessageId: 'client-2', body: userMessage([{ type: 'text', text: 'same prompt' }]) },
+      100
+    )
+    await vi.waitFor(() => expect(session.dispatchWaiters).toHaveLength(1))
+    const secondUuid = session.dispatchWaiters[0]!.sentUuid
+
+    expect(
+      resolveClaudeReplayWaiter(session, userReplayFrame('provider-a-late', 'same prompt'))
+    ).toBe(false)
+    expect(session.dispatchWaiters[0]).toMatchObject({ sentUuid: secondUuid })
+
+    resolveClaudeReplayWaiter(session, userReplayFrame(secondUuid, 'same prompt'))
+    await expect(second).resolves.toMatchObject({ providerIdentity: { uuid: secondUuid } })
+  })
+
   it('removes only its own waiter when a later send fails', async () => {
     const session = sessionFor()
     const first = dispatchClaudeTurn(

src/main/claude/claude-structured-dispatch.ts

@@ -74,7 +74,7 @@ export function resolveClaudeReplayWaiter(
     // candidate on one side of the timeout boundary; with active and retired
     // candidates present, identical prompts are intentionally left unknown.
     const replayContentKey = claudeDispatchContentKey(envelope.content)
-    if (session.retiredDispatchWaiters.length === 0) {
+    if (!session.replayContentFallbackBlocked && session.retiredDispatchWaiters.length === 0) {
       const compatible = session.dispatchWaiters.filter(
         (candidate) => candidate.replayContentKey === replayContentKey
       )
@@ -82,7 +82,7 @@ export function resolveClaudeReplayWaiter(
         settleWaiter(session, compatible[0]!, uuid)
         return compatible[0]!.dispatchSequence === session.dispatchSequence
       }
-    } else if (session.dispatchWaiters.length === 0) {
+    } else if (!session.replayContentFallbackBlocked && session.dispatchWaiters.length === 0) {
       const lateCompatible = session.retiredDispatchWaiters.filter(
         (candidate) => candidate.replayContentKey === replayContentKey
       )
@@ -184,6 +184,7 @@ function retireWaiter(session: ClaudeSession, waiter: ClaudeDispatchWaiter): voi
     waiter.retired = true
     session.retiredDispatchWaiters.push(waiter)
     if (session.retiredDispatchWaiters.length > MAX_RETIRED_DISPATCH_WAITERS) {
+      session.replayContentFallbackBlocked = true
       session.retiredDispatchWaiters.splice(
         0,
         session.retiredDispatchWaiters.length - MAX_RETIRED_DISPATCH_WAITERS

src/main/claude/claude-structured-options.test.ts

@@ -12,6 +12,7 @@ function sessionFor(setModel: ClaudeSession['connection']['setModel']): ClaudeSe
     prompts: {} as ClaudeSession['prompts'],
     dispatchWaiters: [],
     retiredDispatchWaiters: [],
+    replayContentFallbackBlocked: false,
     dispatchSequence: 0,
     optionMutationSequence: 0,
     options: new Map(),

src/main/claude/claude-structured-session-publication.ts

@@ -44,6 +44,8 @@ export function createClaudeSessionPublication(input: {
       acquisitionGeneration: input.acquisitionGeneration,
       prompts: input.prompts,
       dispatchWaiters: [],
+      retiredDispatchWaiters: [],
+      replayContentFallbackBlocked: false,
       dispatchSequence: 0,
       optionMutationSequence: 0,
       options: new Map(input.options),
@@ -52,6 +54,7 @@ export function createClaudeSessionPublication(input: {
         ...(model ? { model } : {}),
         ...(effort ? { effort } : {})
       },
+      restoreSkippedOptions: new Set(),
       translator: input.translator,
       events: input.events
     }

src/main/claude/claude-structured-session-state.ts

@@ -101,6 +101,8 @@ export type ClaudeSession = {
   dispatchWaiters: ClaudeDispatchWaiter[]
   /** Bounded identities for dispatches whose ack was unknown when they returned. */
   retiredDispatchWaiters: ClaudeDispatchWaiter[]
+  /** Once a retired waiter is evicted, legacy content-only replay matching is unsafe. */
+  replayContentFallbackBlocked: boolean
   options: Map<string, string>
   reportedOptions: { model?: string; effort?: string }
   restoreSkippedOptions: Set<string>