feat: auto-detect gemini binary path, LLM health check in status

- Setup wizard auto-detects gemini binary via `which`, saves full path
  so systemd service can find it without user PATH
- `mcpctl status` tests LLM provider health (gemini: quick prompt test,
  ollama: health check, API providers: key stored confirmation)
- Shows error details inline: "gemini-cli / gemini-2.5-flash (not authenticated)"

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

src/cli/tests/commands/config-setup.test.ts

@@ -42,6 +42,7 @@ function buildDeps(overrides: {
   secrets?: Record<string, string>;
   answers?: unknown[];
   fetchModels?: ConfigSetupDeps['fetchModels'];
+  whichBinary?: ConfigSetupDeps['whichBinary'];
 } = {}): ConfigSetupDeps {
   return {
     configDeps: { configDir: tempDir },
@@ -49,6 +50,7 @@ function buildDeps(overrides: {
     log: (...args: string[]) => logs.push(args.join(' ')),
     prompt: mockPrompt(overrides.answers ?? []),
     fetchModels: overrides.fetchModels ?? vi.fn(async () => []),
+    whichBinary: overrides.whichBinary ?? vi.fn(async () => '/usr/bin/gemini'),
   };
 }
 
@@ -76,26 +78,49 @@ describe('config setup wizard', () => {
   });
 
   describe('provider: gemini-cli', () => {
-    it('saves gemini-cli with selected model', async () => {
-      // Answers: select provider, select model, confirm custom binary=false
-      const deps = buildDeps({ answers: ['gemini-cli', 'gemini-2.5-flash', false] });
+    it('auto-detects binary path and saves config', async () => {
+      // Answers: select provider, select model (no binary prompt — auto-detected)
+      const deps = buildDeps({
+        answers: ['gemini-cli', 'gemini-2.5-flash'],
+        whichBinary: vi.fn(async () => '/home/user/.npm-global/bin/gemini'),
+      });
       await runSetup(deps);
 
       const config = readConfig();
-      expect((config.llm as Record<string, unknown>).provider).toBe('gemini-cli');
-      expect((config.llm as Record<string, unknown>).model).toBe('gemini-2.5-flash');
+      const llm = config.llm as Record<string, unknown>;
+      expect(llm.provider).toBe('gemini-cli');
+      expect(llm.model).toBe('gemini-2.5-flash');
+      expect(llm.binaryPath).toBe('/home/user/.npm-global/bin/gemini');
+      expect(logs.some((l) => l.includes('Found gemini at'))).toBe(true);
       cleanup();
     });
 
-    it('saves gemini-cli with custom model and binary path', async () => {
-      // Answers: select provider, select custom, enter model name, confirm custom binary=true, enter path
-      const deps = buildDeps({ answers: ['gemini-cli', '__custom__', 'gemini-3.0-flash', true, '/opt/gemini'] });
+    it('prompts for manual path when binary not found', async () => {
+      // Answers: select provider, select model, enter manual path
+      const deps = buildDeps({
+        answers: ['gemini-cli', 'gemini-2.5-flash', '/opt/gemini'],
+        whichBinary: vi.fn(async () => null),
+      });
+      await runSetup(deps);
+
+      const config = readConfig();
+      const llm = config.llm as Record<string, unknown>;
+      expect(llm.binaryPath).toBe('/opt/gemini');
+      expect(logs.some((l) => l.includes('not found'))).toBe(true);
+      cleanup();
+    });
+
+    it('saves gemini-cli with custom model', async () => {
+      // Answers: select provider, select custom, enter model name
+      const deps = buildDeps({
+        answers: ['gemini-cli', '__custom__', 'gemini-3.0-flash'],
+        whichBinary: vi.fn(async () => '/usr/bin/gemini'),
+      });
       await runSetup(deps);
 
       const config = readConfig();
       const llm = config.llm as Record<string, unknown>;
       expect(llm.model).toBe('gemini-3.0-flash');
-      expect(llm.binaryPath).toBe('/opt/gemini');
       cleanup();
     });
   });
@@ -250,7 +275,7 @@ describe('config setup wizard', () => {
 
   describe('output messages', () => {
     it('shows restart instruction', async () => {
-      const deps = buildDeps({ answers: ['gemini-cli', 'gemini-2.5-flash', false] });
+      const deps = buildDeps({ answers: ['gemini-cli', 'gemini-2.5-flash'] });
       await runSetup(deps);
 
       expect(logs.some((l) => l.includes('systemctl --user restart mcplocal'))).toBe(true);
@@ -258,7 +283,7 @@ describe('config setup wizard', () => {
     });
 
     it('shows configured provider and model', async () => {
-      const deps = buildDeps({ answers: ['gemini-cli', 'gemini-2.5-flash', false] });
+      const deps = buildDeps({ answers: ['gemini-cli', 'gemini-2.5-flash'] });
       await runSetup(deps);
 
       expect(logs.some((l) => l.includes('gemini-cli') && l.includes('gemini-2.5-flash'))).toBe(true);