fix: add missing branching files and TypeScript fix

- Add BranchRevivalCard, BranchTransitionBar, useHandoff, useResolutionOutputs, SessionQueuePage
- Fix useFlowPilotSession: add is_branching/active_branch_id defaults

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

frontend/src/hooks/useFlowPilotSession.ts

@@ -92,6 +92,8 @@ export function useFlowPilotSession(): UseFlowPilotSession {
         ticket_data: null,
         steps: [firstStep],
         conversation_messages: [],
+        is_branching: false,
+        active_branch_id: null,
       })
       setAllSteps([firstStep])
       setCurrentStep(firstStep)

frontend/src/hooks/useHandoff.ts

@@ -0,0 +1,49 @@
+import { useState, useCallback } from 'react'
+import { handoffsApi } from '@/api'
+import type { HandoffCreateRequest, HandoffResponse, QueueItemResponse } from '@/types/branching'
+import { toast } from '@/lib/toast'
+
+export function useHandoff() {
+  const [isSubmitting, setIsSubmitting] = useState(false)
+  const [queue, setQueue] = useState<QueueItemResponse[]>([])
+  const [isLoadingQueue, setIsLoadingQueue] = useState(false)
+
+  const createHandoff = useCallback(async (sessionId: string, data: HandoffCreateRequest): Promise<HandoffResponse | null> => {
+    setIsSubmitting(true)
+    try {
+      const result = await handoffsApi.createHandoff(sessionId, data)
+      toast.success(data.intent === 'park' ? 'Session parked' : 'Session escalated')
+      return result
+    } catch {
+      toast.error('Failed to hand off session')
+      return null
+    } finally {
+      setIsSubmitting(false)
+    }
+  }, [])
+
+  const claimHandoff = useCallback(async (sessionId: string, handoffId: string): Promise<HandoffResponse | null> => {
+    try {
+      const result = await handoffsApi.claimHandoff(sessionId, handoffId)
+      toast.success('Session claimed')
+      return result
+    } catch {
+      toast.error('Failed to claim session')
+      return null
+    }
+  }, [])
+
+  const loadQueue = useCallback(async () => {
+    setIsLoadingQueue(true)
+    try {
+      const items = await handoffsApi.getQueue()
+      setQueue(items)
+    } catch {
+      toast.error('Failed to load queue')
+    } finally {
+      setIsLoadingQueue(false)
+    }
+  }, [])
+
+  return { isSubmitting, queue, isLoadingQueue, createHandoff, claimHandoff, loadQueue }
+}

frontend/src/hooks/useResolutionOutputs.ts

@@ -0,0 +1,43 @@
+import { useState, useCallback } from 'react'
+import { resolutionsApi } from '@/api'
+import type { ResolutionOutputResponse, PushDestination } from '@/types/branching'
+import { toast } from '@/lib/toast'
+
+export function useResolutionOutputs(sessionId: string) {
+  const [outputs, setOutputs] = useState<ResolutionOutputResponse[]>([])
+  const [isLoading, setIsLoading] = useState(false)
+
+  const loadOutputs = useCallback(async () => {
+    setIsLoading(true)
+    try {
+      const data = await resolutionsApi.getOutputs(sessionId)
+      setOutputs(data.outputs)
+    } catch {
+      toast.error('Failed to load resolution outputs')
+    } finally {
+      setIsLoading(false)
+    }
+  }, [sessionId])
+
+  const editOutput = useCallback(async (outputId: string, content: string) => {
+    try {
+      const updated = await resolutionsApi.editOutput(sessionId, outputId, { edited_content: content })
+      setOutputs(prev => prev.map(o => o.id === updated.id ? updated : o))
+      toast.success('Changes saved')
+    } catch {
+      toast.error('Failed to save changes')
+    }
+  }, [sessionId])
+
+  const pushOutput = useCallback(async (outputId: string, destination: PushDestination) => {
+    try {
+      await resolutionsApi.pushOutput(sessionId, outputId, { destination })
+      toast.success(`Pushed to ${destination}`)
+      await loadOutputs()
+    } catch {
+      toast.error('Failed to push output')
+    }
+  }, [sessionId, loadOutputs])
+
+  return { outputs, isLoading, loadOutputs, editOutput, pushOutput }
+}