Add LearnHouse Deployment Isolation Toolkit and debugging tools

- Introduced comprehensive documentation for diagnosing and fixing deployment isolation issues between DEV and LIVE instances.
- Implemented enhanced debug API endpoints for deployment verification, URL hardcoding detection, cookie isolation testing, and session configuration checks.
- Created scripts for visual demonstration of cookie isolation, enhanced debugging deployment, and verification of NextAuth cookie isolation.
- Developed a master isolation verification script to run all isolation checks in sequence and summarize results.
- Added detailed README and environment variable guidelines for proper deployment isolation.

ISOLATION_TOOLKIT_README.md

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+# LearnHouse Deployment Isolation Toolkit
+
+This toolkit provides comprehensive tools and documentation for diagnosing and fixing deployment isolation issues between DEV and LIVE LearnHouse instances.
+
+## Background
+
+We identified cross-deployment contamination issues between DEV (adr-lms.whitex.cloud) and LIVE (edu.adradviser.ro) deployments, including:
+
+- Data contamination (both deployments accessing the same database)
+- Session mixing (cookies being shared between deployments)
+- Inconsistent user experience (hardcoded URLs pointing to the wrong environment)
+
+## Isolation Toolkit Components
+
+### Documentation
+
+1. **[ISOLATION_IMPLEMENTATION_CHECKLIST.md](./ISOLATION_IMPLEMENTATION_CHECKLIST.md)**  
+   Step-by-step checklist for implementing complete isolation between deployments.
+
+2. **[DATABASE_ISOLATION_FIX.md](./DATABASE_ISOLATION_FIX.md)**  
+   Detailed explanation of database isolation issues and how to fix them.
+
+3. **[DEPLOYMENT_TROUBLESHOOTING.md](./DEPLOYMENT_TROUBLESHOOTING.md)**  
+   Guide for troubleshooting deployment and configuration issues.
+
+4. **[ENHANCED_DEBUG_TOOLS.md](./ENHANCED_DEBUG_TOOLS.md)**  
+   Documentation for the enhanced debugging endpoints.
+
+5. **[COOLIFY_ENV_VARS.md](./COOLIFY_ENV_VARS.md)**  
+   Environment variable templates for Coolify deployments.
+
+### Debugging Tools
+
+1. **Debug API Endpoints**
+   - `/api/v1/debug/deployment` - Get detailed deployment configuration
+   - `/api/v1/debug/urls` - Scan for hardcoded URLs in the frontend bundle
+   - `/api/v1/debug/cookies` - Test cookie isolation between deployments
+   - `/api/v1/debug/session` - Verify session configuration
+
+2. **Verification Scripts**
+   - `verify-isolation.sh` - Basic isolation verification
+   - `verify-enhanced-isolation.sh` - Comprehensive isolation checks
+   - `verify-db-isolation.sh` - Database-specific isolation verification
+   - `test-nextauth-cookie-isolation.sh` - NextAuth cookie isolation test
+
+3. **Visual Demonstration Tools**
+   - `create-cookie-demo.sh` - Creates an HTML tool to visually demonstrate cookie isolation
+
+### Deployment Scripts
+
+1. **`deploy-enhanced-debug.sh`**  
+   Deploys the enhanced debugging endpoints to diagnose isolation issues.
+
+2. **`deploy-isolation-fix.sh`**  
+   Applies the complete isolation fixes to both deployments.
+
+## Getting Started
+
+1. **Deploy debugging tools:**
+   ```bash
+   ./deploy-enhanced-debug.sh
+   ```
+
+2. **Run the enhanced isolation verification:**
+   ```bash
+   ./verify-enhanced-isolation.sh
+   ```
+
+3. **Test cookie isolation:**
+   ```bash
+   ./test-nextauth-cookie-isolation.sh
+   ```
+
+4. **Create a visual cookie isolation demo:**
+   ```bash
+   ./create-cookie-demo.sh
+   # Then open cookie-isolation-demo.html in your browser
+   ```
+
+5. **Follow the implementation checklist:**
+   See [ISOLATION_IMPLEMENTATION_CHECKLIST.md](./ISOLATION_IMPLEMENTATION_CHECKLIST.md)
+
+## Key Environment Variables for Isolation
+
+For proper isolation, ensure each deployment has unique values for these variables:
+
+### DEV Environment
+```
+DEPLOYMENT_NAME=DEV
+LEARNHOUSE_SQL_CONNECTION_STRING=postgresql://learnhouse_dev:PASSWORD@db-dev:5432/learnhouse_dev
+LEARNHOUSE_COOKIE_DOMAIN=adr-lms.whitex.cloud
+NEXT_PUBLIC_LEARNHOUSE_DOMAIN=adr-lms.whitex.cloud
+NEXT_PUBLIC_LEARNHOUSE_TOP_DOMAIN=whitex.cloud
+```
+
+### LIVE Environment
+```
+DEPLOYMENT_NAME=LIVE
+LEARNHOUSE_SQL_CONNECTION_STRING=postgresql://learnhouse:PASSWORD@db-live:5432/learnhouse
+LEARNHOUSE_COOKIE_DOMAIN=edu.adradviser.ro
+NEXT_PUBLIC_LEARNHOUSE_DOMAIN=edu.adradviser.ro
+NEXT_PUBLIC_LEARNHOUSE_TOP_DOMAIN=adradviser.ro
+```
+
+## Troubleshooting
+
+If you encounter issues during the isolation process, refer to [DEPLOYMENT_TROUBLESHOOTING.md](./DEPLOYMENT_TROUBLESHOOTING.md).