Migrate from Supabase to direct PostgreSQL connection

- Replace @supabase/supabase-js with native pg library
- Rewrite database.js to use PostgreSQL connection pool
- Update server.js with PostgreSQL connection testing
- Create postgres-schema.sql with complete database schema
- Add apply-schema.js script for easy schema deployment
- Update all documentation (README.md, DEPLOYMENT.md, deploy.sh)
- Remove Supabase-specific files and references
- Update db.config.example.js with PostgreSQL format

README_DB_CONFIG.md

@@ -1,45 +1,46 @@
-# Database Configuration Setup - Supabase
+# Database Configuration Setup - PostgreSQL
 
 ## Overview
 Database credentials are stored in a separate configuration file (`db.config.js`) that is **NOT committed to GitHub** for security reasons.
 
-This project now uses **Supabase** (PostgreSQL) instead of MySQL.
+This project uses **PostgreSQL** for persistent data storage.
 
 ## Files
 
 ### 1. `db.config.example.js` (Committed to Git)
-Template file showing the required Supabase configuration structure.
+Template file showing the required PostgreSQL configuration structure.
 
 ### 2. `db.config.js` (NOT Committed - in .gitignore)
-Contains actual Supabase credentials. This file must be created manually.
+Contains actual PostgreSQL credentials. This file must be created manually.
 
 ### 3. `.gitignore`
 Ensures `db.config.js` is never committed to the repository.
 
 ## Quick Setup
 
-See **[SUPABASE_SETUP.md](SUPABASE_SETUP.md)** for detailed step-by-step instructions.
-
 ### Quick Start
 
-1. **Create Supabase project** at [app.supabase.com](https://app.supabase.com)
-2. **Copy credentials** from Project Settings → API
-3. **Update `db.config.js`:**
+1. **Ensure PostgreSQL is running** on your server
+2. **Create the database:** `CREATE DATABASE connect5;`
+3. **Run the schema:** `psql -h HOST -U postgres -d connect5 -f postgres-schema.sql`
+4. **Create `db.config.js`:**
    ```javascript
    module.exports = {
-       supabaseUrl: 'https://xxxxx.supabase.co',
-       supabaseAnonKey: 'eyJhbGci...',
-       supabasePassword: 't1hWsackxbYzRIPD'
+       HOST: '202.171.184.108',
+       USER: 'postgres',
+       PASSWORD: 'your-password',
+       DB: 'connect5',
+       dialect: 'postgres',
+       pool: { max: 5, min: 0, acquire: 30000, idle: 10000 }
    };
    ```
-4. **Run SQL schema** in Supabase SQL Editor (see SUPABASE_SETUP.md)
 5. **Start server:** `npm start`
 
 ## Security Features
 
 ✅ **Credentials not in git** - `db.config.js` is in `.gitignore`  
 ✅ **Template provided** - `db.config.example.js` shows the structure  
-✅ **Supabase RLS** - Row Level Security policies protect data  
+✅ **Connection pooling** - Efficient database connection management  
 ✅ **Separate config** - Easy to update without touching main code  
 
 ## Troubleshooting
@@ -49,28 +50,29 @@ See **[SUPABASE_SETUP.md](SUPABASE_SETUP.md)** for detailed step-by-step instruc
 **Solution:** Create the `db.config.js` file:
 ```bash
 cp db.config.example.js db.config.js
-# Then edit with your Supabase credentials
+# Then edit with your PostgreSQL credentials
 ```
 
-### Error: Invalid API key
+### Error: ECONNREFUSED or connection timeout
 
 **Solution:** Check your credentials in `db.config.js`:
-- Verify `supabaseUrl` is correct
-- Verify `supabaseAnonKey` (should start with `eyJ...`)
-- Get credentials from Supabase dashboard → Project Settings → API
+- Verify `HOST` is accessible
+- Verify `USER` and `PASSWORD` are correct
+- Ensure PostgreSQL server is running: `sudo systemctl status postgresql`
+- Check firewall allows connection to port 5432
 
 ### Error: Table 'players' does not exist
 
 **Solution:**
-- Run the SQL schema in Supabase SQL Editor
-- See SUPABASE_SETUP.md Step 4 for the complete schema
+- Run the SQL schema: `psql -h HOST -U postgres -d connect5 -f postgres-schema.sql`
+- See README.md for setup instructions
 
 ## Important Notes
 
 ⚠️ **NEVER commit `db.config.js` to git**  
 ⚠️ **Keep credentials secure**  
-⚠️ **Use different projects for dev/prod**  
-⚠️ **The anon key is safe for client-side use** (protected by RLS)  
+⚠️ **Use different databases for dev/prod**  
+⚠️ **Configure PostgreSQL firewall rules appropriately**  
 
 ## File Structure
 
@@ -80,7 +82,6 @@ Connect-5/
 ├── db.config.js             ← Your credentials (NOT in git)
 ├── .gitignore               ← Protects db.config.js
 ├── database.js              ← Imports from db.config.js
-├── supabase-functions.sql   ← Helper functions for Supabase
-├── SUPABASE_SETUP.md        ← Detailed setup guide
+├── postgres-schema.sql      ← Database schema
 └── README_DB_CONFIG.md      ← This file
 ```