Migrate Tír na nÓg landing page to Next.js

Summary of changes:
- Created the 'feature/migration-nextjs' branch.
- Initialized a Next.js project with React components and App Router structure.
- Created reusable UI components: Viewport, World, Room, and Door in 'app/components/'.
- Implemented spatial navigation logic (WASD/Arrows and clicks) using React 'useState' and 'useEffect' in 'app/page.js'.
- Migrated the Tír na nÓg pixel-art aesthetic and layout transitions into 'app/globals.css'.
- Configured a Gitea Runner CI/CD workflow in '.gitea/workflows/deploy.yml' for automated builds and linting.
- Added a '.gitignore' file to manage project artifacts.

Co-authored-by: micmug <185775013+micmug@users.noreply.github.com>

app/page.js

@@ -0,0 +1,70 @@
+'use client';
+import { useState, useEffect } from 'react';
+import Viewport from './components/Viewport';
+import World from './components/World';
+import Room from './components/Room';
+import Door from './components/Door';
+export default function Home() {
+  const [currentPos, setCurrentPos] = useState({ x: 0, y: 0 });
+  const gridSize = { width: 2, height: 2 };
+  const navigateTo = (targetStr) => {
+    const [x, y] = targetStr.split(',').map(Number);
+    if (!isNaN(x) && !isNaN(y)) { setCurrentPos({ x, y }); }
+  };
+  const moveRelative = (dx, dy) => {
+    setCurrentPos((prev) => {
+      const newX = prev.x + dx;
+      const newY = prev.y + dy;
+      if (newX >= 0 && newX < gridSize.width && newY >= 0 && newY < gridSize.height) {
+        return { x: newX, y: newY };
+      }
+      return prev;
+    });
+  };
+  useEffect(() => {
+    const handleKeyDown = (e) => {
+      switch (e.key.toLowerCase()) {
+        case 'arrowup': case 'w': moveRelative(0, -1); break;
+        case 'arrowdown': case 's': moveRelative(0, 1); break;
+        case 'arrowleft': case 'a': moveRelative(-1, 0); break;
+        case 'arrowright': case 'd': moveRelative(1, 0); break;
+      }
+    };
+    window.addEventListener('keydown', handleKeyDown);
+    return () => window.removeEventListener('keydown', handleKeyDown);
+  }, []);
+  return (
+    <Viewport>
+      <World currentPos={currentPos}>
+        <Room id="room-0-0" isActive={currentPos.x === 0 && currentPos.y === 0}>
+          <div className="content"><h1>Tír na nÓg</h1><p>Welcome to the Land of Eternal Youth.</p></div>
+          <div className="doors">
+            <Door direction="east" target="1,0" label="To the Meadow →" onNavigate={navigateTo} />
+            <Door direction="south" target="0,1" label="Down the Alleys ↓" onNavigate={navigateTo} />
+          </div>
+        </Room>
+        <Room id="room-1-0" isActive={currentPos.x === 1 && currentPos.y === 0}>
+          <div className="content"><h2>The Meadow</h2><p>Where pixels bloom and legends grow.</p></div>
+          <div className="doors">
+            <Door direction="west" target="0,0" label="← Back to the Gate" onNavigate={navigateTo} />
+            <Door direction="south" target="1,1" label="To the Portal ↓" onNavigate={navigateTo} />
+          </div>
+        </Room>
+        <Room id="room-0-1" isActive={currentPos.x === 0 && currentPos.y === 1}>
+          <div className="content"><h2>The Alleys</h2><p>Navigating the narrow paths of creation.</p></div>
+          <div className="doors">
+            <Door direction="north" target="0,0" label="↑ Up to the Gate" onNavigate={navigateTo} />
+            <Door direction="east" target="1,1" label="To the Portal →" onNavigate={navigateTo} />
+          </div>
+        </Room>
+        <Room id="room-1-1" isActive={currentPos.x === 1 && currentPos.y === 1}>
+          <div className="content"><h2>The Portal</h2><p>Step through to join the faebits.</p></div>
+          <div className="doors">
+            <Door direction="north" target="1,0" label="↑ Up to the Meadow" onNavigate={navigateTo} />
+            <Door direction="west" target="0,1" label="← Back to the Alleys" onNavigate={navigateTo} />
+          </div>
+        </Room>
+      </World>
+    </Viewport>
+  );
+}