feat: Implement tournament schedule tab and fix E2E tests (#27)

## Summary

This PR implements the tournament schedule tab functionality and fixes all remaining E2E test failures.

### Changes Included

1. **Tournament Schedule Feature**
   - Added tournament schedule page at `/admin/tournaments/[id]/schedule`
   - Implemented "Generate Schedule" button functionality
   - Added schedule generation logic for round-robin tournaments

2. **E2E Test Fixes**
   - Fixed database connection issues in production builds
   - Improved test reliability with better error handling and debugging
   - Updated test infrastructure to use environment variables instead of hardcoded values

3. **CI/CD Updates**
   - Added E2E test job to PR workflow
   - Configured tests to run against development database
   - Moved database password to Gitea secrets

4. **Code Quality**
   - Removed hardcoded passwords from codebase
   - Improved Prisma client configuration
   - Enhanced authentication and navigation components

### Test Results
All 16 E2E test scenarios are now passing:
- Authentication tests: ✅
- Registration tests: ✅
- Tournament schedule tests: ✅
- Player schedule tests: ✅
- Admin navigation tests: ✅

### Database Configuration
- Tests run against `euchre_camp_dev` database
- Production builds use environment variables for database configuration
- Database password stored in Gitea secrets as `DB_PASSWORD`

### CI Pipeline
The PR workflow now includes:
1. Unit tests
2. E2E tests (using production build)
3. Version bump analysis

E2E tests must pass before PR can be merged.

Reviewed-on: #27
Co-authored-by: David Gwilliam <dhgwilliam@gmail.com>
Co-committed-by: David Gwilliam <dhgwilliam@gmail.com>

src/app/admin/users/components/EditUserForm.tsx

@@ -35,10 +35,16 @@ export default function EditUserForm({ user, availablePlayers }: EditUserFormPro
         body: JSON.stringify(formData),
       })
 
-      const data = await response.json()
-
       if (!response.ok) {
-        throw new Error(data.error || "Failed to update user")
+        try {
+          const errorData = await response.json()
+          throw new Error(errorData.error || "Failed to update user")
+        } catch (jsonError) {
+          if (jsonError instanceof Error && jsonError.message !== "Failed to update user") {
+            throw jsonError
+          }
+          throw new Error(`Failed to update user: ${response.status} ${response.statusText}`)
+        }
       }
 
       setSuccess("User updated successfully!")