feat: LLM provider configuration, secret store, and setup wizard

Add secure credential storage (GNOME Keyring + file fallback),
LLM provider config in ~/.mcpctl/config.json, interactive setup
wizard (mcpctl config setup), and wire configured provider into
mcplocal for smart pagination summaries.

- Secret store: SecretStore interface, GnomeKeyringStore, FileSecretStore
- Config schema: LlmConfigSchema with provider/model/url/binaryPath
- Setup wizard: arrow-key provider/model selection, dynamic model fetch
- Provider factory: creates ProviderRegistry from config + secrets
- Status: shows LLM line with hint when not configured
- 572 tests passing across all packages

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

src/mcplocal/tests/http/config.test.ts

@@ -0,0 +1,65 @@
+import { describe, it, expect, vi, afterEach } from 'vitest';
+import { loadLlmConfig } from '../../src/http/config.js';
+import { existsSync, readFileSync } from 'node:fs';
+
+vi.mock('node:fs', async () => {
+  const actual = await vi.importActual<typeof import('node:fs')>('node:fs');
+  return {
+    ...actual,
+    existsSync: vi.fn(),
+    readFileSync: vi.fn(),
+  };
+});
+
+afterEach(() => {
+  vi.restoreAllMocks();
+});
+
+describe('loadLlmConfig', () => {
+  it('returns undefined when config file does not exist', () => {
+    vi.mocked(existsSync).mockReturnValue(false);
+    expect(loadLlmConfig()).toBeUndefined();
+  });
+
+  it('returns undefined when config has no llm section', () => {
+    vi.mocked(existsSync).mockReturnValue(true);
+    vi.mocked(readFileSync).mockReturnValue(JSON.stringify({ mcplocalUrl: 'http://localhost:3200' }));
+    expect(loadLlmConfig()).toBeUndefined();
+  });
+
+  it('returns undefined when provider is none', () => {
+    vi.mocked(existsSync).mockReturnValue(true);
+    vi.mocked(readFileSync).mockReturnValue(JSON.stringify({ llm: { provider: 'none' } }));
+    expect(loadLlmConfig()).toBeUndefined();
+  });
+
+  it('returns LLM config when provider is configured', () => {
+    vi.mocked(existsSync).mockReturnValue(true);
+    vi.mocked(readFileSync).mockReturnValue(JSON.stringify({
+      llm: { provider: 'anthropic', model: 'claude-haiku-3-5-20241022' },
+    }));
+    const result = loadLlmConfig();
+    expect(result).toEqual({ provider: 'anthropic', model: 'claude-haiku-3-5-20241022' });
+  });
+
+  it('returns full LLM config with all fields', () => {
+    vi.mocked(existsSync).mockReturnValue(true);
+    vi.mocked(readFileSync).mockReturnValue(JSON.stringify({
+      llm: { provider: 'vllm', model: 'my-model', url: 'http://gpu:8000' },
+    }));
+    const result = loadLlmConfig();
+    expect(result).toEqual({ provider: 'vllm', model: 'my-model', url: 'http://gpu:8000' });
+  });
+
+  it('returns undefined on malformed JSON', () => {
+    vi.mocked(existsSync).mockReturnValue(true);
+    vi.mocked(readFileSync).mockReturnValue('NOT JSON!!!');
+    expect(loadLlmConfig()).toBeUndefined();
+  });
+
+  it('returns undefined on read error', () => {
+    vi.mocked(existsSync).mockReturnValue(true);
+    vi.mocked(readFileSync).mockImplementation(() => { throw new Error('EACCES'); });
+    expect(loadLlmConfig()).toBeUndefined();
+  });
+});