feat: build CLI core framework with Commander.js

Add CLI entry point with Commander.js, config management (~/.mcpctl/config.json
with Zod validation), output formatters (table/json/yaml), config and status
commands with dependency injection for testing. Fix sanitizeString regex ordering.
67 tests passing.

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

src/cli/tests/formatters/output.test.ts

@@ -0,0 +1,41 @@
+import { describe, it, expect } from 'vitest';
+import { formatJson, formatYaml } from '../../src/formatters/output.js';
+
+describe('formatJson', () => {
+  it('formats object as indented JSON', () => {
+    const result = formatJson({ key: 'value', num: 42 });
+    expect(JSON.parse(result)).toEqual({ key: 'value', num: 42 });
+    expect(result).toContain('\n'); // indented
+  });
+
+  it('formats arrays', () => {
+    const result = formatJson([1, 2, 3]);
+    expect(JSON.parse(result)).toEqual([1, 2, 3]);
+  });
+
+  it('handles null and undefined values', () => {
+    const result = formatJson({ a: null, b: undefined });
+    const parsed = JSON.parse(result) as Record<string, unknown>;
+    expect(parsed['a']).toBeNull();
+    expect('b' in parsed).toBe(false); // undefined stripped by JSON
+  });
+});
+
+describe('formatYaml', () => {
+  it('formats object as YAML', () => {
+    const result = formatYaml({ key: 'value', num: 42 });
+    expect(result).toContain('key: value');
+    expect(result).toContain('num: 42');
+  });
+
+  it('formats arrays', () => {
+    const result = formatYaml(['a', 'b']);
+    expect(result).toContain('- a');
+    expect(result).toContain('- b');
+  });
+
+  it('does not end with trailing newline', () => {
+    const result = formatYaml({ x: 1 });
+    expect(result.endsWith('\n')).toBe(false);
+  });
+});