fix: ship the missing /ponytail-help command on Claude Code and OpenCode (#62)

Ships the previously-missing /ponytail-help adapter files (commands/ponytail-help.toml, .opencode/command/ponytail-help.md) and adds tests/commands.test.js, a parity guard asserting every pi-registered command has both adapter files. Thanks @hooni0918.

tests/commands.test.js

@@ -0,0 +1,39 @@
+#!/usr/bin/env node
+// Every ponytail command the pi extension registers must also ship as a
+// file-based command for the hosts that need one: Claude Code (commands/*.toml,
+// which Gemini CLI reuses) and OpenCode (.opencode/command/*.md). /ponytail-help
+// was advertised in the README and the help card but missing both files; this
+// guards that drift -- a registered command with no adapter file fails here.
+
+const test = require('node:test');
+const assert = require('node:assert/strict');
+const fs = require('fs');
+const path = require('path');
+
+const root = path.join(__dirname, '..');
+
+// pi-extension registers the canonical command set.
+const piSource = fs.readFileSync(path.join(root, 'pi-extension', 'index.js'), 'utf8');
+const commands = [...piSource.matchAll(/registerCommand\(["']([\w-]+)["']/g)].map((m) => m[1]);
+
+test('pi registers at least the base command', () => {
+  assert.ok(commands.includes('ponytail'), 'expected pi to register a ponytail command');
+});
+
+test('every registered command ships a Claude commands/*.toml', () => {
+  for (const name of commands) {
+    assert.ok(
+      fs.existsSync(path.join(root, 'commands', `${name}.toml`)),
+      `missing commands/${name}.toml`,
+    );
+  }
+});
+
+test('every registered command ships an OpenCode .opencode/command/*.md', () => {
+  for (const name of commands) {
+    assert.ok(
+      fs.existsSync(path.join(root, '.opencode', 'command', `${name}.md`)),
+      `missing .opencode/command/${name}.md`,
+    );
+  }
+});