refactor: move setup scripts out of src/ to reduce build token count

Setup scripts are standalone CLI tools run via tsx with no runtime
imports from the main app. Moving them out of src/ excludes them from
the tsc build output and reduces the compiled bundle size.

- git mv src/setup/ setup/
- Fix imports to use ../src/logger.js and ../src/config.js
- Update package.json, vitest.config.ts, SKILL.md references
- Fix platform tests to be cross-platform (macOS + Linux)

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

setup/environment.test.ts

@@ -0,0 +1,103 @@
+import { describe, it, expect, beforeEach } from 'vitest';
+import fs from 'fs';
+
+import Database from 'better-sqlite3';
+
+/**
+ * Tests for the environment check step.
+ *
+ * Verifies: config detection, Docker/AC detection, DB queries.
+ */
+
+describe('environment detection', () => {
+  it('detects platform correctly', async () => {
+    const { getPlatform } = await import('./platform.js');
+    const platform = getPlatform();
+    expect(['macos', 'linux', 'unknown']).toContain(platform);
+  });
+});
+
+describe('registered groups DB query', () => {
+  let db: Database.Database;
+
+  beforeEach(() => {
+    db = new Database(':memory:');
+    db.exec(`CREATE TABLE IF NOT EXISTS registered_groups (
+      jid TEXT PRIMARY KEY,
+      name TEXT NOT NULL,
+      folder TEXT NOT NULL UNIQUE,
+      trigger_pattern TEXT NOT NULL,
+      added_at TEXT NOT NULL,
+      container_config TEXT,
+      requires_trigger INTEGER DEFAULT 1
+    )`);
+  });
+
+  it('returns 0 for empty table', () => {
+    const row = db.prepare(
+      'SELECT COUNT(*) as count FROM registered_groups',
+    ).get() as { count: number };
+    expect(row.count).toBe(0);
+  });
+
+  it('returns correct count after inserts', () => {
+    db.prepare(
+      `INSERT INTO registered_groups (jid, name, folder, trigger_pattern, added_at, requires_trigger)
+       VALUES (?, ?, ?, ?, ?, ?)`,
+    ).run('123@g.us', 'Group 1', 'group-1', '@Andy', '2024-01-01T00:00:00.000Z', 1);
+
+    db.prepare(
+      `INSERT INTO registered_groups (jid, name, folder, trigger_pattern, added_at, requires_trigger)
+       VALUES (?, ?, ?, ?, ?, ?)`,
+    ).run('456@g.us', 'Group 2', 'group-2', '@Andy', '2024-01-01T00:00:00.000Z', 1);
+
+    const row = db.prepare(
+      'SELECT COUNT(*) as count FROM registered_groups',
+    ).get() as { count: number };
+    expect(row.count).toBe(2);
+  });
+});
+
+describe('credentials detection', () => {
+  it('detects ANTHROPIC_API_KEY in env content', () => {
+    const content = 'SOME_KEY=value\nANTHROPIC_API_KEY=sk-ant-test123\nOTHER=foo';
+    const hasCredentials = /^(CLAUDE_CODE_OAUTH_TOKEN|ANTHROPIC_API_KEY)=/m.test(content);
+    expect(hasCredentials).toBe(true);
+  });
+
+  it('detects CLAUDE_CODE_OAUTH_TOKEN in env content', () => {
+    const content = 'CLAUDE_CODE_OAUTH_TOKEN=token123';
+    const hasCredentials = /^(CLAUDE_CODE_OAUTH_TOKEN|ANTHROPIC_API_KEY)=/m.test(content);
+    expect(hasCredentials).toBe(true);
+  });
+
+  it('returns false when no credentials', () => {
+    const content = 'ASSISTANT_NAME="Andy"\nOTHER=foo';
+    const hasCredentials = /^(CLAUDE_CODE_OAUTH_TOKEN|ANTHROPIC_API_KEY)=/m.test(content);
+    expect(hasCredentials).toBe(false);
+  });
+});
+
+describe('Docker detection logic', () => {
+  it('commandExists returns boolean', async () => {
+    const { commandExists } = await import('./platform.js');
+    expect(typeof commandExists('docker')).toBe('boolean');
+    expect(typeof commandExists('nonexistent_binary_xyz')).toBe('boolean');
+  });
+});
+
+describe('WhatsApp auth detection', () => {
+  it('detects non-empty auth directory logic', () => {
+    // Simulate the check: directory exists and has files
+    const hasAuth = (authDir: string) => {
+      try {
+        return fs.existsSync(authDir) && fs.readdirSync(authDir).length > 0;
+      } catch {
+        return false;
+      }
+    };
+
+    // Non-existent directory
+    expect(hasAuth('/tmp/nonexistent_auth_dir_xyz')).toBe(false);
+  });
+});