Complete Phase 2: Frontend implementation with React + TypeScript

Frontend Features:
- React 18 + Vite + TypeScript + Tailwind CSS + Zustand
- JWT authentication with automatic token refresh
- Tree library with search and category filtering
- Full tree navigation (decision/action/solution nodes)
- Session management with notes and completion
- Session history with export (Markdown/Text/HTML)
- ErrorBoundary for graceful error handling

Backend Fixes:
- CORS: Added port 5174 to allowed origins
- Sessions: Fixed JSONB datetime serialization (mode='json')

Documentation:
- Updated PROGRESS.md with Phase 2 completion
- Updated 03-DEVELOPMENT-ROADMAP.md with checked items
- Added PHASE-2.5-PERSONAL-BRANCHING.md spec

Seed Data:
- Added backend/scripts/seed_data.py with Password Reset tree

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

frontend/src/api/trees.ts

@@ -0,0 +1,57 @@
+import apiClient from './client'
+import type { Tree, TreeListItem, TreeCreate, TreeUpdate } from '@/types'
+
+export interface TreeListParams {
+  page?: number
+  size?: number
+  category?: string
+  include_inactive?: boolean
+}
+
+export interface TreeListResponse {
+  items: TreeListItem[]
+  total: number
+  page: number
+  size: number
+  pages: number
+}
+
+export const treesApi = {
+  async list(params?: TreeListParams): Promise<TreeListItem[]> {
+    const response = await apiClient.get<TreeListItem[]>('/trees', { params })
+    return response.data
+  },
+
+  async get(id: string): Promise<Tree> {
+    const response = await apiClient.get<Tree>(`/trees/${id}`)
+    return response.data
+  },
+
+  async create(data: TreeCreate): Promise<Tree> {
+    const response = await apiClient.post<Tree>('/trees', data)
+    return response.data
+  },
+
+  async update(id: string, data: TreeUpdate): Promise<Tree> {
+    const response = await apiClient.put<Tree>(`/trees/${id}`, data)
+    return response.data
+  },
+
+  async delete(id: string): Promise<void> {
+    await apiClient.delete(`/trees/${id}`)
+  },
+
+  async categories(): Promise<string[]> {
+    const response = await apiClient.get<string[]>('/trees/categories')
+    return response.data
+  },
+
+  async search(query: string, category?: string): Promise<TreeListItem[]> {
+    const response = await apiClient.get<TreeListItem[]>('/trees/search', {
+      params: { q: query, category },
+    })
+    return response.data
+  },
+}
+
+export default treesApi