diff --git a/CLAUDE.md b/CLAUDE.md
index 97213db4..82294687 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -1,7 +1,7 @@
 # CLAUDE.md - Patherly Project Context
 
 > **Purpose:** This file provides Claude Code with essential context for working on the Patherly project.
-> **Last Updated:** February 3, 2026
+> **Last Updated:** February 3, 2026 (improved by claude-md-improver)
 
 ---
 
@@ -25,6 +25,7 @@
 - **Database:** PostgreSQL with Docker (container name: `patherly_postgres`)
 
 ### What's Complete
+
 - User authentication (JWT, register, login, refresh, invite codes)
 - Trees CRUD with full-text search
 - Sessions tracking with decisions
@@ -63,9 +64,11 @@
   - Rating/review system with verified use tracking
 
 ### What's In Progress
+
 - Step Library frontend UI (Phase 2.5 continuation)
 
 ### Deployment
+
 - **Production:** Railway (app.patherly.com / api.patherly.com)
 - **PR Environments:** Enabled - auto-created for each pull request
 
@@ -74,6 +77,7 @@
 ## Tech Stack
 
 ### Backend
+
 - **Framework:** Python FastAPI
 - **Database:** PostgreSQL 16 (async via SQLAlchemy 2.0 + asyncpg)
 - **Migrations:** Alembic
@@ -81,6 +85,7 @@
 - **Validation:** Pydantic v2
 
 ### Frontend
+
 - **Framework:** React 19 + Vite + TypeScript
 - **Styling:** Tailwind CSS v3
 - **State:** Zustand (with immer + zundo for undo/redo)
@@ -183,6 +188,42 @@ patherly/
 
 ---
 
+## Environment Variables
+
+### Backend (.env)
+
+**Required in `backend/.env`:**
+```bash
+# Application
+APP_NAME=Patherly
+DEBUG=true  # Set false in production
+
+# Database (matches docker-compose.yml)
+DATABASE_URL=postgresql+asyncpg://postgres:postgres@localhost:5432/patherly
+DATABASE_URL_SYNC=postgresql://postgres:postgres@localhost:5432/patherly
+
+# JWT Settings - CHANGE THESE IN PRODUCTION
+SECRET_KEY=<generate with: openssl rand -hex 32>
+ACCESS_TOKEN_EXPIRE_MINUTES=30
+REFRESH_TOKEN_EXPIRE_MINUTES=10080
+
+# Auth
+REQUIRE_INVITE_CODE=true  # Set false to allow open registration
+```
+
+**Railway-specific (production):**
+```bash
+ALLOW_RAILWAY_ORIGINS=true  # Enables CORS for PR environments
+```
+
+### Frontend (.env.local - optional)
+
+```bash
+VITE_API_URL=http://localhost:8000  # Override API URL
+```
+
+---
+
 ## Development Commands
 
 ### Start Development Environment
@@ -191,40 +232,73 @@ patherly/
 # Terminal 1: Start PostgreSQL
 docker start patherly_postgres
 
-# Terminal 2: Backend
-cd C:\Dev\Projects\patherly\patherly\backend
+# Terminal 2: Backend (from project root)
+cd backend
+# Windows:
 .\venv\Scripts\Activate
+# Linux/Mac:
+source venv/bin/activate
 uvicorn app.main:app --reload
 
-# Terminal 3: Frontend
-cd C:\Dev\Projects\patherly\patherly\frontend
+# Terminal 3: Frontend (from project root)
+cd frontend
 npm run dev
 ```
 
 ### URLs
+
 - Frontend: http://localhost:5173
 - Backend API: http://localhost:8000
 - API Docs: http://localhost:8000/api/docs
 
 ### Run Tests
+
 ```powershell
-cd C:\Dev\Projects\patherly\patherly\backend
-.\venv\Scripts\Activate
+# From project root
+cd backend
+
+# First time only: create test database
+docker exec -it patherly_postgres psql -U postgres -c "CREATE DATABASE patherly_test;"
+
+# Install test dependencies (if not already installed)
+pip install -r requirements-dev.txt
+
+# Run tests
 pytest
 ```
 
-### Run Seed Scripts
+### Frontend Operations
+
 ```powershell
-cd C:\Dev\Projects\patherly\patherly\backend
-.\venv\Scripts\Activate
+# From project root
+cd frontend
+
+# Build for production
+npm run build
+
+# Preview production build
+npm run preview
+
+# Lint code
+npm run lint
+```
+
+### Run Seed Scripts
+
+```powershell
+# From project root
+cd backend
 pip install httpx  # Required for seed scripts
 python -m scripts.seed_trees
 ```
 
 ### Database Operations
+
 ```powershell
-# Run migrations
+# From project root
 cd backend
+
+# Run migrations
 alembic upgrade head
 
 # Create new migration
@@ -241,6 +315,7 @@ docker exec -it patherly_postgres psql -U postgres -d patherly
 **ALWAYS read [LESSONS-LEARNED.md](LESSONS-LEARNED.md) before making changes!**
 
 ### DateTime Handling (Critical)
+
 ```python
 # CORRECT - Always use timezone-aware datetimes
 from datetime import datetime, timezone
@@ -253,6 +328,7 @@ datetime.utcnow()  # Deprecated, returns naive datetime
 ```
 
 ### React State: Don't Store Object Snapshots
+
 ```tsx
 // WRONG - Snapshot won't update when store changes
 const [editingNode, setEditingNode] = useState<TreeStructure | null>(null)
@@ -263,6 +339,7 @@ const editingNode = editingNodeId ? findNode(editingNodeId) : null
 ```
 
 ### Modal Draft State: Don't Overwrite Store-Managed Fields
+
 ```tsx
 // WRONG - Overwrites children with stale snapshot
 const handleSave = () => {
@@ -277,14 +354,17 @@ const handleSave = () => {
 ```
 
 ### Database Name
+
 - Database name is `patherly` (not `decision_tree`)
 - Update `.env` if you see the old name
 
 ### Virtual Environment
+
 - Always check for `(venv)` prefix before running pip
 - Don't use `--break-system-packages` when venv is active
 
 ### PostgreSQL NULL Casting for UUID Columns
+
 ```sql
 -- WRONG - PostgreSQL infers NULL as text type
 INSERT INTO tree_tags (name, slug, team_id)
@@ -297,6 +377,7 @@ SELECT 'tag', 'slug', NULL::uuid as team_id  -- Works!
 Always use `NULL::uuid` when inserting NULL values into UUID columns in raw SQL.
 
 ### SQLAlchemy Async: Avoid Lazy Loading on New Objects
+
 ```python
 # WRONG - Triggers lazy load which fails in async context
 new_tree = Tree(...)
@@ -316,6 +397,7 @@ await db.execute(
 Accessing relationships on newly created objects triggers lazy loading, which fails in async SQLAlchemy. Use direct SQL inserts for junction tables instead.
 
 ### React Router: Clear Dirty State Before Navigation
+
 ```tsx
 // WRONG - Navigation triggers before dirty flag is cleared
 const newTree = await treesApi.create(data)
@@ -329,118 +411,58 @@ navigate(`/trees/${newTree.id}/edit`)  // Blocker won't fire
 ```
 When using `useBlocker` for unsaved changes, always clear the dirty flag before programmatic navigation.
 
+### CORS: Include Both allow_origins AND allow_origin_regex
+
+```python
+# WRONG - Custom domains ignored when using regex
+if settings.ALLOW_RAILWAY_ORIGINS:
+    app.add_middleware(
+        CORSMiddleware,
+        allow_origin_regex=r"https://.*\.up\.railway\.app",  # Only matches Railway domains!
+        # ...
+    )
+
+# CORRECT - Include both for custom domains + Railway PR environments
+if settings.ALLOW_RAILWAY_ORIGINS:
+    app.add_middleware(
+        CORSMiddleware,
+        allow_origins=settings.allowed_origins,  # Custom domains like app.patherly.com
+        allow_origin_regex=r"https://.*\.up\.railway\.app",  # Railway PR domains
+        # ...
+    )
+```
+When using `allow_origin_regex` for wildcard patterns, also include `allow_origins` for explicit custom domains. The regex alone won't match custom domains like `app.patherly.com`.
+
 ---
 
 ## API Endpoints Reference
 
-### Authentication
-```
-POST /api/v1/auth/register     - Register (requires invite code by default)
-POST /api/v1/auth/login        - Login (form data)
-POST /api/v1/auth/login/json   - Login (JSON body)
-POST /api/v1/auth/refresh      - Refresh access token
-GET  /api/v1/auth/me           - Get current user
-POST /api/v1/auth/logout       - Logout
-```
+**Full API documentation:** http://localhost:8000/api/docs (interactive OpenAPI/Swagger UI)
 
-### Trees
-```
-GET    /api/v1/trees              - List trees (filters: category_id, tags, folder_id)
-POST   /api/v1/trees              - Create tree (supports tags, category_id)
-GET    /api/v1/trees/categories   - Get legacy string categories
-GET    /api/v1/trees/search       - Full-text search
-GET    /api/v1/trees/{id}         - Get tree (includes tags, category_info)
-PUT    /api/v1/trees/{id}         - Update tree
-DELETE /api/v1/trees/{id}         - Soft delete
-```
+**Quick reference:**
+- **Auth:** `/api/v1/auth/*` - register, login, refresh, logout, me
+- **Trees:** `/api/v1/trees/*` - CRUD, search, categories (supports filters: category_id, tags, folder_id)
+- **Sessions:** `/api/v1/sessions/*` - start, track, complete, export (markdown/text/html)
+- **Tags:** `/api/v1/tags/*` - manage tree tags, autocomplete search
+- **Folders:** `/api/v1/folders/*` - user folders with subfolder hierarchy (max 3 levels deep)
+- **Categories:** `/api/v1/categories/*` - tree categories (global + team-specific)
+- **Step Categories:** `/api/v1/step-categories/*` - step categories for library
+- **Step Library:** `/api/v1/steps/*` - reusable steps, ratings, reviews, full-text search
+- **Invite Codes:** `/api/v1/invite-codes/*` - admin management
 
-### Categories (NEW)
-```
-GET    /api/v1/categories         - List categories (global + user's team)
-POST   /api/v1/categories         - Create category (team/global admin)
-GET    /api/v1/categories/{id}    - Get category
-PUT    /api/v1/categories/{id}    - Update category
-DELETE /api/v1/categories/{id}    - Soft delete category
-```
+**Key constraints:**
+- Folder hierarchy: max 3 levels deep (root → child → grandchild)
+- Step ratings: 1-5 stars with optional review text
+- Categories and tags: support both global and team-specific scoping
 
-### Tags (NEW)
-```
-GET    /api/v1/tags               - List tags (global + user's team)
-GET    /api/v1/tags/search        - Autocomplete search
-POST   /api/v1/tags               - Create tag
-GET    /api/v1/tags/{id}          - Get tag
-GET    /api/v1/tags/trees/{id}    - Get tree's tags
-POST   /api/v1/tags/trees/{id}    - Add tags to tree
-PUT    /api/v1/tags/trees/{id}    - Replace tree's tags
-DELETE /api/v1/tags/trees/{id}/{slug} - Remove tag from tree
-```
-
-### Folders
-```
-GET    /api/v1/folders            - List user's folders (includes parent_id)
-POST   /api/v1/folders            - Create folder (supports parent_id for subfolders)
-GET    /api/v1/folders/{id}       - Get folder
-PUT    /api/v1/folders/{id}       - Update folder (supports moving via parent_id)
-DELETE /api/v1/folders/{id}       - Delete folder (cascades to subfolders)
-POST   /api/v1/folders/reorder    - Reorder folders
-POST   /api/v1/folders/{id}/trees - Add tree to folder
-GET    /api/v1/folders/{id}/trees - Get folder's tree IDs
-DELETE /api/v1/folders/{id}/trees/{tree_id} - Remove tree from folder
-```
-
-**Folder hierarchy constraints:**
-- Max nesting depth: 3 levels (root → child → grandchild)
-- Same folder name allowed under different parents
-- Moving folders validates cycle prevention
-
-### Step Categories (NEW)
-```
-GET    /api/v1/step-categories         - List categories (global + user's team)
-POST   /api/v1/step-categories         - Create category (admin/team_admin)
-GET    /api/v1/step-categories/{id}    - Get category
-PUT    /api/v1/step-categories/{id}    - Update category
-DELETE /api/v1/step-categories/{id}    - Soft delete category
-```
-
-### Step Library (NEW)
-```
-GET    /api/v1/steps              - List steps (filters: visibility, category_id, tags, min_rating, step_type, sort_by)
-POST   /api/v1/steps              - Create step
-GET    /api/v1/steps/{id}         - Get step details
-PUT    /api/v1/steps/{id}         - Update step (owner/admin)
-DELETE /api/v1/steps/{id}         - Soft delete step (owner/admin)
-GET    /api/v1/steps/search       - Full-text search (?q=query)
-GET    /api/v1/steps/tags/popular - Popular tags list
-
-# Rating endpoints
-POST   /api/v1/steps/{id}/rate    - Rate a step (1-5 stars + optional review)
-PUT    /api/v1/steps/{id}/rate    - Update your rating
-DELETE /api/v1/steps/{id}/rate    - Remove your rating
-GET    /api/v1/steps/{id}/reviews - Get reviews for a step
-```
-
-### Sessions
-```
-GET  /api/v1/sessions             - List user's sessions
-POST /api/v1/sessions             - Start session
-GET  /api/v1/sessions/{id}        - Get session
-PUT  /api/v1/sessions/{id}        - Update session
-POST /api/v1/sessions/{id}/complete - Complete session
-POST /api/v1/sessions/{id}/export   - Export (md/txt/html)
-```
-
-### Invite Codes
-```
-GET  /api/v1/invite-codes         - List codes (admin)
-POST /api/v1/invite-codes         - Create code (admin)
-GET  /api/v1/invite-codes/validate/{code} - Validate code
-```
+For detailed parameters, request/response schemas, and examples, visit the API docs.
 
 ---
 
 ## Data Models
 
 ### Tree Structure (JSONB)
+
 ```typescript
 interface TreeStructure {
   id: string
@@ -472,6 +494,7 @@ interface TreeStructure {
 ```
 
 ### Session Decisions (JSONB)
+
 ```typescript
 interface Decision {
   node_id: string
@@ -487,18 +510,21 @@ interface Decision {
 ## Frontend Patterns
 
 ### State Management
+
 - **Auth:** `useAuthStore` - Zustand with localStorage persistence
 - **Theme:** `useThemeStore` - Dark/light/system preference
 - **Tree Editor:** `useTreeEditorStore` - Zustand + immer + zundo (undo/redo)
 - **User Preferences:** `useUserPreferencesStore` - Zustand with localStorage persistence (export format default)
 
 ### Component Guidelines
+
 - Use `cn()` from `@/lib/utils` for Tailwind class merging
 - Use Lucide icons (no `title` prop - wrap in `<span>` instead)
 - Modals: Use fixed header/footer with scrollable body
 - Forms: Show field-level validation errors
 
 ### API Client Pattern
+
 ```typescript
 import api from '@/api/client'
 
@@ -536,6 +562,7 @@ const response = await api.get('/api/v1/trees')
 ## Coding Standards
 
 ### Python (Backend)
+
 - Use type hints everywhere
 - Use async/await for database operations
 - Use Pydantic for validation
@@ -543,6 +570,7 @@ const response = await api.get('/api/v1/trees')
 - Always use `DateTime(timezone=True)` for timestamps
 
 ### TypeScript (Frontend)
+
 - Enable strict mode (when ready)
 - Use TypeScript interfaces for all data structures
 - Prefer `const` over `let`
@@ -550,6 +578,7 @@ const response = await api.get('/api/v1/trees')
 - Extract reusable logic into custom hooks
 
 ### Git
+
 - Commit message format: `type: description`
 - Types: `feat`, `fix`, `refactor`, `docs`, `test`, `chore`
 - Always include `Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>`
@@ -559,6 +588,7 @@ const response = await api.get('/api/v1/trees')
 ## Future Roadmap
 
 ### Phase 2.5 (In Progress)
+
 - ✅ Step Categories database and API
 - ✅ Step Library database schema (step_library, step_ratings, step_usage_log)
 - ✅ Step Library CRUD API with search and ratings
@@ -570,12 +600,14 @@ const response = await api.get('/api/v1/trees')
 - 🔲 Tree forking and sharing
 
 ### Phase 3 (Planned)
+
 - File attachments (screenshots, logs)
 - Offline mode (Service Workers + IndexedDB)
 - Client context system
 - Analytics dashboard
 
 ### Phase 4 (Planned)
+
 - API & integrations (ConnectWise, Kaseya)
 - PowerShell automation execution
 - Enterprise features (SSO, white-labeling)
@@ -585,25 +617,59 @@ const response = await api.get('/api/v1/trees')
 ## Troubleshooting
 
 ### Backend won't start
+
 1. Check Docker: `docker ps` - is `patherly_postgres` running?
 2. Check `.env` - is DATABASE_URL correct (`patherly` not `decision_tree`)?
 3. Check venv: is `(venv)` prefix showing?
 
 ### Frontend compile errors
+
 1. Check `frontend/src/lib/utils.ts` exists (provides `cn()` function)
 2. Run `npm install` to ensure dependencies are installed
 
 ### Tests failing
+
 1. Create test database: `docker exec -it patherly_postgres psql -U postgres -c "CREATE DATABASE patherly_test;"`
 2. Install dev deps: `pip install -r requirements-dev.txt`
 3. Ensure pytest-asyncio version: `pip install pytest-asyncio==0.24.0`
 
 ### API 500 errors
+
 1. Check server logs for datetime errors (timezone issue)
 2. Ensure all datetimes use `datetime.now(timezone.utc)`
 
 ---
 
+## Git Patterns
+
+**Always gitignore:**
+```
+# Secrets and local config
+backend/.env
+.claude.local.md
+
+# Dependencies
+backend/venv/
+frontend/node_modules/
+
+# Build artifacts
+frontend/dist/
+backend/**/__pycache__/
+*.pyc
+
+# Railway CLI (local tooling only)
+/node_modules/
+/package.json
+/package-lock.json
+
+# IDE
+.vscode/
+.idea/
+*.swp
+```
+
+---
+
 ## Quick Reference
 
 | What | Where |
@@ -619,12 +685,14 @@ const response = await api.get('/api/v1/trees')
 ## Railway Deployment
 
 ### Production
+
 - **Frontend:** https://app.patherly.com
 - **Backend:** https://api.patherly.com
 - **Database:** Railway-managed PostgreSQL
 - Deploys automatically on push to `main`
 
 ### PR Environments
+
 Railway creates isolated preview environments for each pull request.
 
 **Workflow:**
@@ -656,6 +724,54 @@ Railway creates isolated preview environments for each pull request.
 **Debug Endpoints (available in PR environments):**
 - `/debug/cors` - Check CORS configuration (allow_railway_origins, cors_mode)
 
+### Railway CLI (Local)
+
+The Railway CLI can be installed locally for managing deployments, viewing logs, and checking service status.
+
+**Setup on a new machine:**
+
+```powershell
+# 1. Install Railway CLI via npm (in project root)
+cd C:\Dev\Projects\patherly
+npm init -y
+npm install @railway/cli
+
+# 2. Login to Railway
+./node_modules/.bin/railway login
+
+# 3. Link to the project
+./node_modules/.bin/railway link
+# Select: selfless-grace → production
+```
+
+**Common Commands:**
+
+```powershell
+# Check service status
+./node_modules/.bin/railway service status --service patherly
+./node_modules/.bin/railway service status --all
+
+# View logs
+./node_modules/.bin/railway service logs --service patherly
+
+# Check environment variables
+./node_modules/.bin/railway variables --service patherly
+
+# Deploy new code (from backend directory)
+cd backend && ../node_modules/.bin/railway up --service patherly
+
+# Redeploy existing build
+./node_modules/.bin/railway service redeploy --service patherly --yes
+```
+
+**Services:**
+
+- `patherly` - Backend API
+- `hopeful-liberation` - Frontend
+- `Postgres` - Database
+
+**Note:** The `node_modules/`, `package.json`, and `package-lock.json` files for the Railway CLI are gitignored (local tooling only).
+
 ---
 
 ## Contact