Complete tactic recognition module with tests and real-time integration

- Add comprehensive test suite (20 tests) for tactic detection
- Fix pawn detection threshold bug (200 -> 100 centipawns)
- Add error handling to uciToSan for invalid moves
- Integrate tactical data into Tutor component for real-time feedback
- Pass missedTactics from ChessGame to Tutor via props
- Update LLM prompt to explain missed tactical opportunities
- Fix Jest configuration to handle react-markdown ESM issues
- All 50 tests passing

jest.setup.ts

@@ -3,3 +3,9 @@ import '@testing-library/jest-dom'
 // Mock scrollIntoView for JSDOM
 window.HTMLElement.prototype.scrollIntoView = jest.fn();
 window.HTMLMediaElement.prototype.play = () => Promise.resolve();
+
+// Mock react-markdown to avoid ESM issues in Jest
+jest.mock('react-markdown', () => ({
+    __esModule: true,
+    default: (props: any) => props.children,
+}));