feat: wire remaining PostHog events across all key user actions (#111)

- export_generated: session copy, copy-for-ticket, download
- ai_feature_used: copilot, assistant chat, session-to-flow, KB accelerator, flow assist
- psa_connected: ConnectWise integration creation
- session_shared: share link creation
- flow_created: troubleshooting editor, procedural editor, session-to-flow

All 9 events from the product analytics plan are now fully wired.

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

frontend/src/pages/account/IntegrationsPage.tsx

@@ -1,5 +1,6 @@
 import { useEffect, useState } from 'react'
 import { Plug, CheckCircle2, AlertCircle, Loader2, Pencil, Trash2, Shield, History, Ticket, Users, Zap, Save } from 'lucide-react'
+import { analytics } from '@/lib/analytics'
 import { PageMeta } from '@/components/common/PageMeta'
 import { integrationsApi } from '@/api/integrations'
 import type { PsaConnectionResponse, PsaConnectionCreate, PsaConnectionUpdate, PsaConnectionTestResponse } from '@/types'
@@ -97,6 +98,7 @@ export function IntegrationsPage() {
       }
       const created = await integrationsApi.createConnection(payload)
       setConnection(created)
+      analytics.psaConnected({ provider: 'connectwise' })
       setMode('view')
       setForm(emptyForm)
     } catch (err) {