fix: convert antfarm from broken submodule to regular directory

Fixes Gitea 500 error caused by invalid submodule reference.
Converted antfarm from pseudo-submodule (missing .gitmodules) to
regular directory with all source files.

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

antfarm/landing/__tests__/landing.test.js

@@ -0,0 +1,48 @@
+import { readFileSync, existsSync } from 'fs';
+import { resolve, dirname } from 'path';
+import { fileURLToPath } from 'url';
+import { describe, it } from 'node:test';
+import assert from 'node:assert/strict';
+
+const __dirname = dirname(fileURLToPath(import.meta.url));
+const landingDir = resolve(__dirname, '..');
+
+describe('Landing page', () => {
+  it('index.html exists', () => {
+    assert.ok(existsSync(resolve(landingDir, 'index.html')));
+  });
+
+  it('style.css exists', () => {
+    assert.ok(existsSync(resolve(landingDir, 'style.css')));
+  });
+
+  it('index.html contains required sections', () => {
+    const html = readFileSync(resolve(landingDir, 'index.html'), 'utf-8');
+    assert.ok(html.includes('id="features"'), 'missing features section');
+    assert.ok(html.includes('id="quickstart"'), 'missing quickstart section');
+    assert.ok(html.includes('id="commands"'), 'missing commands section');
+    assert.ok(html.includes('<title>'), 'missing title');
+    assert.ok(html.includes('meta name="viewport"'), 'missing viewport meta');
+    assert.ok(html.includes('meta name="description"'), 'missing description meta');
+  });
+
+  it('index.html references style.css', () => {
+    const html = readFileSync(resolve(landingDir, 'index.html'), 'utf-8');
+    assert.ok(html.includes('style.css'));
+  });
+
+  it('style.css contains essential rules', () => {
+    const css = readFileSync(resolve(landingDir, 'style.css'), 'utf-8');
+    assert.ok(css.includes('.hero'), 'missing hero styles');
+    assert.ok(css.includes('.feature-grid'), 'missing feature grid');
+    assert.ok(css.includes('@media'), 'missing responsive styles');
+  });
+
+  it('all internal links have valid targets', () => {
+    const html = readFileSync(resolve(landingDir, 'index.html'), 'utf-8');
+    const anchors = [...html.matchAll(/href="#([^"]+)"/g)].map(m => m[1]);
+    for (const id of anchors) {
+      assert.ok(html.includes(`id="${id}"`), `missing target for #${id}`);
+    }
+  });
+});