Reorganize: Move all skills to skills/ folder

- Created skills/ directory
- Moved 272 skills to skills/ subfolder
- Kept agents/ at root level
- Kept installation scripts and docs at root level

Repository structure:
- skills/           - All 272 skills from skills.sh
- agents/           - Agent definitions
- *.sh, *.ps1       - Installation scripts
- README.md, etc.   - Documentation

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

skills/plugins/claude-hud/tests/stdin.test.js

@@ -0,0 +1,32 @@
+import { test } from 'node:test';
+import assert from 'node:assert/strict';
+import { readStdin } from '../dist/stdin.js';
+
+test('readStdin returns null for TTY input', async () => {
+  const originalIsTTY = process.stdin.isTTY;
+  Object.defineProperty(process.stdin, 'isTTY', { value: true, configurable: true });
+
+  try {
+    const result = await readStdin();
+    assert.equal(result, null);
+  } finally {
+    Object.defineProperty(process.stdin, 'isTTY', { value: originalIsTTY, configurable: true });
+  }
+});
+
+test('readStdin returns null on stream errors', async () => {
+  const originalIsTTY = process.stdin.isTTY;
+  const originalSetEncoding = process.stdin.setEncoding;
+  Object.defineProperty(process.stdin, 'isTTY', { value: false, configurable: true });
+  process.stdin.setEncoding = () => {
+    throw new Error('boom');
+  };
+
+  try {
+    const result = await readStdin();
+    assert.equal(result, null);
+  } finally {
+    process.stdin.setEncoding = originalSetEncoding;
+    Object.defineProperty(process.stdin, 'isTTY', { value: originalIsTTY, configurable: true });
+  }
+});