feat: add instance lifecycle management with restart, inspect, and CLI commands

Adds restart/inspect methods to InstanceService, state validation for stop,
REST endpoints for restart and inspect, and full CLI command suite for
instance list/start/stop/restart/remove/logs/inspect.

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

src/mcpd/src/services/instance.service.ts

@@ -1,8 +1,16 @@
 import type { McpInstance } from '@prisma/client';
 import type { IMcpInstanceRepository, IMcpServerRepository } from '../repositories/interfaces.js';
-import type { McpOrchestrator, ContainerSpec } from './orchestrator.js';
+import type { McpOrchestrator, ContainerSpec, ContainerInfo } from './orchestrator.js';
 import { NotFoundError } from './mcp-server.service.js';
 
+export class InvalidStateError extends Error {
+  readonly statusCode = 409;
+  constructor(message: string) {
+    super(message);
+    this.name = 'InvalidStateError';
+  }
+}
+
 export class InstanceService {
   constructor(
     private instanceRepo: IMcpInstanceRepository,
@@ -71,6 +79,9 @@ export class InstanceService {
 
   async stop(id: string): Promise<McpInstance> {
     const instance = await this.getById(id);
+    if (instance.status === 'STOPPED') {
+      throw new InvalidStateError(`Instance '${id}' is already stopped`);
+    }
     if (!instance.containerId) {
       return this.instanceRepo.updateStatus(id, 'STOPPED');
     }
@@ -87,6 +98,37 @@ export class InstanceService {
     }
   }
 
+  async restart(id: string): Promise<McpInstance> {
+    const instance = await this.getById(id);
+
+    // Stop if running
+    if (instance.containerId && (instance.status === 'RUNNING' || instance.status === 'STARTING')) {
+      try {
+        await this.orchestrator.stopContainer(instance.containerId);
+      } catch {
+        // Container may already be stopped
+      }
+      try {
+        await this.orchestrator.removeContainer(instance.containerId, true);
+      } catch {
+        // Container may already be gone
+      }
+    }
+
+    await this.instanceRepo.delete(id);
+
+    // Start a fresh instance for the same server
+    return this.start(instance.serverId);
+  }
+
+  async inspect(id: string): Promise<ContainerInfo> {
+    const instance = await this.getById(id);
+    if (!instance.containerId) {
+      throw new InvalidStateError(`Instance '${id}' has no container`);
+    }
+    return this.orchestrator.inspectContainer(instance.containerId);
+  }
+
   async remove(id: string): Promise<void> {
     const instance = await this.getById(id);