feat: initial tictactoe web app with CI/CD pipeline

- Express app serving vanilla JS 2-player TicTacToe game
- Dockerfile (multi-stage node:18-slim)
- Jenkinsfile (K8s pod: test → Harbor push → Helm bump → Gitea push)
- Helm chart v1.0.0 with HTTPRoute for tictactoe.fireflylab.local

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

public/game.js

@@ -0,0 +1,61 @@
+(function () {
+  const WINS = [
+    [0,1,2],[3,4,5],[6,7,8],
+    [0,3,6],[1,4,7],[2,5,8],
+    [0,4,8],[2,4,6]
+  ];
+
+  let board, current, over;
+  const cells = document.querySelectorAll('.cell');
+  const status = document.getElementById('status');
+  const resetBtn = document.getElementById('reset');
+
+  function init() {
+    board = Array(9).fill(null);
+    current = 'X';
+    over = false;
+    cells.forEach(c => {
+      c.textContent = '';
+      c.className = 'cell';
+    });
+    status.textContent = "Player X's turn";
+  }
+
+  function checkWinner() {
+    for (const [a, b, c] of WINS) {
+      if (board[a] && board[a] === board[b] && board[a] === board[c]) {
+        return { winner: board[a], line: [a, b, c] };
+      }
+    }
+    return board.every(Boolean) ? { winner: null, draw: true } : null;
+  }
+
+  function handleClick(e) {
+    const idx = parseInt(e.target.dataset.index);
+    if (over || board[idx]) return;
+
+    board[idx] = current;
+    const cell = cells[idx];
+    cell.textContent = current;
+    cell.classList.add('taken', current.toLowerCase());
+
+    const result = checkWinner();
+    if (result) {
+      over = true;
+      if (result.draw) {
+        status.textContent = "It's a draw!";
+      } else {
+        result.line.forEach(i => cells[i].classList.add('winner'));
+        status.textContent = `Player ${result.winner} wins!`;
+      }
+    } else {
+      current = current === 'X' ? 'O' : 'X';
+      status.textContent = `Player ${current}'s turn`;
+    }
+  }
+
+  cells.forEach(c => c.addEventListener('click', handleClick));
+  resetBtn.addEventListener('click', init);
+
+  init();
+})();