feat(ai-session): add Phase 2 PSA integration, escalation handoff, and session management

Phase 2 of the FlowPilot-First Pivot connecting AI sessions to ConnectWise PSA:

Slice 1 — PSA Ticket Intake:
- FlowPilotEngine accepts psa_ticket intake with graceful CW API fallback
- Ticket picker on intake screen (refactored TicketPickerModal for dual-mode)
- Ticket context card in session sidebar

Slice 2 — Auto Documentation Push:
- PSA documentation service with resolution/escalation note formatting
- Time entry creation via new ConnectWise provider method
- Automatic retry scheduler (APScheduler, 5min interval, 3 retries)
- PSA push status indicators in frontend with manual retry button
- Member mapping warning when CW member not mapped

Slice 3 — Session Pause/Resume & Escalation Handoff:
- Pause/resume endpoints for same-engineer session bookmarking
- Escalation flow: requesting_escalation status, self-escalation blocked
- Enhanced escalation package with LLM-generated hypotheses/suggestions
- Pickup endpoint with continue/fresh resume modes and briefing step
- Escalation queue (sidebar nav + dedicated page)
- SessionBriefing component with continue/fresh choice UI
- EscalateModal with PSA-aware button text

Slice 4 — Mid-Session Ticket Linking:
- Link ticket retroactively with context injection into system prompt
- Link Ticket button in session sidebar

Slice 5 — FlowPilot PSA Settings:
- Settings tab on IntegrationsPage with 7 configurable options
- Stored as flowpilot_settings JSONB on PsaConnection

Database: 2 migrations (flowpilot_settings, psa_post_log changes, status constraint)

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

frontend/src/api/integrations.ts

@@ -1,6 +1,6 @@
 import { apiClient } from './client'
 import type { PsaConnectionResponse, PsaConnectionCreate, PsaConnectionUpdate, PsaConnectionTestResponse } from '@/types'
-import type { TicketLinkResponse, PSATicketSearchResult, PSATicketInfo, PSATicketStatusItem, PsaPreviewResponse, PsaPostResponse, PsaPostLogEntry, PsaMemberResponse, PsaMemberMappingResponse, AutoMatchResult } from '@/types/integrations'
+import type { TicketLinkResponse, PSATicketSearchResult, PSATicketInfo, PSATicketStatusItem, PsaPreviewResponse, PsaPostResponse, PsaPostLogEntry, PsaMemberResponse, PsaMemberMappingResponse, AutoMatchResult, FlowpilotSettings } from '@/types/integrations'
 
 export const integrationsApi = {
   getConnection: () =>
@@ -27,6 +27,10 @@ export const integrationsApi = {
     apiClient.post<PsaMemberMappingResponse[]>('/integrations/psa/member-mappings', mappings).then(r => r.data),
   autoMatchMembers: () =>
     apiClient.post<AutoMatchResult>('/integrations/psa/member-mappings/auto-match').then(r => r.data),
+  getFlowpilotSettings: (connectionId: string) =>
+    apiClient.get<FlowpilotSettings>(`/integrations/psa/connections/${connectionId}/flowpilot-settings`).then(r => r.data),
+  updateFlowpilotSettings: (connectionId: string, data: Partial<FlowpilotSettings>) =>
+    apiClient.put<FlowpilotSettings>(`/integrations/psa/connections/${connectionId}/flowpilot-settings`, data).then(r => r.data),
 }
 
 export const sessionPsaApi = {