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/TreeEditorPage.tsx

@@ -2,6 +2,7 @@ import { useEffect, useState, useCallback, useRef } from 'react'
 import { useParams, useNavigate, useBlocker } from 'react-router-dom'
 import { useStore } from 'zustand'
 import { Undo2, Redo2, Save, CheckCircle2, Monitor, FileText, Code2, LayoutList, BarChart3, Settings, Download, Sparkles } from 'lucide-react'
+import { analytics } from '@/lib/analytics'
 import { Button } from '@/components/ui/Button'
 import { getMonacoEditor } from '@/components/tree-editor/code-mode'
 import { treesApi } from '@/api/trees'
@@ -364,6 +365,7 @@ export function TreeEditorPage() {
         toast.success('Draft saved successfully')
       } else {
         const newTree = await treesApi.create(treeData as TreeCreate)
+        analytics.flowCreated({ flow_type: 'troubleshooting', method: 'manual' })
         setTreeStatus('draft')
         markSaved()
         toast.success('Draft created successfully')
@@ -443,6 +445,7 @@ export function TreeEditorPage() {
         toast.success('Tree published successfully')
       } else {
         const newTree = await treesApi.create(treeData as TreeCreate)
+        analytics.flowCreated({ flow_type: 'troubleshooting', method: 'manual' })
         setTreeStatus('published')
         markSaved()
         toast.success('Tree published successfully')