Refactor patch test system and add booking edit requests

- Replace patch_test_duration_hours on services with separate
  patch_tests table
- Add user_patch_tests table to track user patch test records
- Add booking edit request system: users can request time changes
- Add admin handlers to list, approve, and reject edit requests
- Add validation to prevent editing completed/cancelled bookings
- Add overlap and closed-day checks for booking edits

backend/testutils/testdb/testdb.go

@@ -76,7 +76,9 @@ func Migrate(t *testing.T, pool *pgxpool.Pool) {
 			"booking_services",
 			"payments",
 			"bookings",
-			"user_service_patch_tests",
+			"user_patch_tests",
+			"patch_tests",
+			"booking_edit_requests",
 			"services",
 			"verification_codes",
 			"user_social_logins",
@@ -196,7 +198,8 @@ func TruncateTables(t *testing.T, pool *pgxpool.Pool) {
 		"booking_services",
 		"payments",
 		"bookings",
-		"user_service_patch_tests",
+		"user_patch_tests",
+		"patch_tests",
 		"services",
 		"admin_notifications",
 		"user_referrals",