test: Add minimal UT infrastructure and fix Issue #227

This commit sets up a minimal, KISS-principle testing infrastructure
for both backend and frontend, and includes the fix for Issue #227.
Backend Changes:
- Add Makefile with test commands (test, test-backend, test-frontend, test-coverage)
- Add example test: config/database_test.go
- Fix Go 1.25 printf format string warnings in trader/auto_trader.go
  (Changed log.Printf to log.Print for non-format strings)
- All backend tests pass ✓
Frontend Changes:
- Add Vitest configuration: web/vitest.config.ts (minimal setup)
- Add test utilities: web/src/test/test-utils.tsx
- Add example test: web/src/App.test.tsx
- Add dependencies: vitest, jsdom, @testing-library/react
- All frontend tests pass ✓
Issue #227 Fix:
- Fix AITradersPage to allow editing traders with disabled models/exchanges
- Change validation to use allModels/allExchanges instead of enabledModels/enabledExchanges
- Add comprehensive tests in web/src/components/AITradersPage.test.tsx
- Fixes: https://github.com/tinkle-community/nofx/issues/227
CI/CD:
- Add GitHub Actions workflow: .github/workflows/test.yml
- Non-blocking tests (continue-on-error: true)
- Runs on push/PR to main and dev branches
Test Results:
- Backend: 1 test passing
- Frontend: 5 tests passing (including 4 for Issue #227)
Co-Authored-By: tinkle-community <tinklefund@gmail.com>

web/src/App.test.tsx

@@ -0,0 +1,7 @@
+import { describe, it, expect } from 'vitest'
+
+describe('Example Test', () => {
+  it('should pass', () => {
+    expect(1 + 1).toBe(2)
+  })
+})