Add PayPal integration and band image upload features

- Implemented complete PayPal payment integration with checkout flow
- Added payments table to database for transaction tracking
- Created image upload functionality for band profiles
- Added gallery management in band profiles
- Updated booking flow to support PayPal payments
- Added payment status display in user profiles
- Included comprehensive documentation for new features

New files:
- upload-handler.php: REST API for image uploads
- paypal-checkout.php: PayPal checkout page
- paypal-process.php: Payment processing backend
- PAYPAL_UPLOAD_FEATURES.md: Complete documentation
- storage/uploads/bands/: Upload directory

Modified files:
- database.sql: Added payments table
- profil.php: Added gallery and payment tracking
- anfrage.php: Integrated PayPal payment option

database.sql

@@ -74,3 +74,17 @@ CREATE TABLE IF NOT EXISTS settings (
     key TEXT PRIMARY KEY,
     value TEXT NOT NULL
 );
+
+CREATE TABLE IF NOT EXISTS payments (
+    id INTEGER PRIMARY KEY AUTOINCREMENT,
+    request_id INTEGER NOT NULL,
+    amount REAL NOT NULL,
+    service_fee REAL NOT NULL,
+    total_amount REAL NOT NULL,
+    paypal_order_id TEXT,
+    paypal_payer_id TEXT,
+    status TEXT NOT NULL DEFAULT 'pending',
+    created_at TEXT DEFAULT CURRENT_TIMESTAMP,
+    completed_at TEXT,
+    FOREIGN KEY(request_id) REFERENCES requests(id) ON DELETE CASCADE
+);