fix: address code review issues in session sharing

- Add useCallback for loadShares in ShareSessionModal (React hook deps)
- Use TreeStructure type instead of Record<string, unknown> for type safety
- Fix login redirect format to match LoginPage's expected state shape

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

frontend/src/components/session/ShareSessionModal.tsx

@@ -1,4 +1,4 @@
-import { useState, useEffect } from 'react'
+import { useState, useEffect, useCallback } from 'react'
 import { X, Copy, Check, Globe, Users, Clock, Trash2, Link2 } from 'lucide-react'
 import type { SessionShare, SessionShareVisibility } from '@/types'
 import { sessionsApi } from '@/api/sessions'
@@ -82,20 +82,7 @@ export function ShareSessionModal({ sessionId, sessionLabel, isOpen, onClose }:
   const [customDatetime, setCustomDatetime] = useState('')
   const [visibilityError, setVisibilityError] = useState<string | null>(null)
 
-  useEffect(() => {
+  const loadShares = useCallback(async () => {
-    if (isOpen) {
-      loadShares()
-      // Reset form state
-      setVisibility('account')
-      setShareName('')
-      setExpirationPreset('never')
-      setCustomDatetime('')
-      setVisibilityError(null)
-      setCopiedShareId(null)
-    }
-  }, [isOpen, sessionId])
-
-  const loadShares = async () => {
     setIsLoadingShares(true)
     try {
       const allShares = await sessionsApi.listMyShares()
@@ -108,7 +95,20 @@ export function ShareSessionModal({ sessionId, sessionLabel, isOpen, onClose }:
     } finally {
       setIsLoadingShares(false)
     }
-  }
+  }, [sessionId])
+
+  useEffect(() => {
+    if (isOpen) {
+      loadShares()
+      // Reset form state
+      setVisibility('account')
+      setShareName('')
+      setExpirationPreset('never')
+      setCustomDatetime('')
+      setVisibilityError(null)
+      setCopiedShareId(null)
+    }
+  }, [isOpen, sessionId, loadShares])
 
   const handleGenerateLink = async () => {
     setIsGenerating(true)

frontend/src/components/session/SharedSessionTreePreview.tsx

@@ -1,7 +1,8 @@
+import type { TreeStructure } from '@/types'
 import { cn } from '@/lib/utils'
 
 interface SharedSessionTreePreviewProps {
-  treeStructure: Record<string, unknown>
+  treeStructure: TreeStructure
   pathTaken: string[]
 }
 

frontend/src/pages/SharedSessionPage.tsx

@@ -97,7 +97,7 @@ export function SharedSessionPage() {
           const status = err.response?.status
           if (status === 401) {
             navigate('/login', {
-              state: { from: `/share/${shareToken}` },
+              state: { from: { pathname: `/share/${shareToken}` } },
               replace: true,
             })
             return
@@ -232,7 +232,7 @@ export function SharedSessionPage() {
           <div className="lg:col-span-2">
             <SessionTimeline
               decisions={data.decisions}
-              treeType={data.tree_structure?.tree_type as string}
+              treeType={data.tree_structure?.tree_type}
               startedAt={data.started_at}
               completedAt={data.completed_at}
               showCopyButtons={false}

frontend/src/types/session.ts

@@ -156,7 +156,7 @@ export interface SharedSessionView {
   session_id: string
   tree_name: string
   tree_description: string | null
-  tree_structure: Record<string, unknown>
+  tree_structure: TreeStructure
   path_taken: string[]
   decisions: DecisionRecord[]
   custom_steps: CustomStep[]