feat: automatic reconciliation loop for MCP server instances

mcpd now runs a periodic reconcileAll() every 30s that:
- Detects crashed/missing containers (syncStatus)
- Cleans up ERROR instances
- Creates replacement pods to match desired replica count

This replaces the old syncStatus-only timer. Servers migrated
from another deployment or recovering from node failures will
automatically get their instances recreated.

6 new tests for reconcileAll covering: missing instances, skip
replicas=0, already-at-count, ERROR cleanup, multi-server,
error isolation.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/mcpd/tests/instance-service.test.ts

@@ -294,4 +294,99 @@ describe('InstanceService', () => {
       expect(result.stdout).toBe('log output');
     });
   });
+
+  describe('reconcileAll', () => {
+    it('creates missing instances for servers with replicas > 0', async () => {
+      const server = makeServer({ id: 'srv-1', name: 'grafana', replicas: 1 });
+      vi.mocked(serverRepo.findAll).mockResolvedValue([server]);
+      vi.mocked(serverRepo.findById).mockResolvedValue(server);
+      // No instances exist
+      vi.mocked(instanceRepo.findAll).mockResolvedValue([]);
+
+      const result = await service.reconcileAll();
+
+      expect(result.reconciled).toBe(1);
+      expect(result.errors).toHaveLength(0);
+      expect(instanceRepo.create).toHaveBeenCalled();
+    });
+
+    it('skips servers with replicas = 0', async () => {
+      const server = makeServer({ id: 'srv-1', replicas: 0 });
+      vi.mocked(serverRepo.findAll).mockResolvedValue([server]);
+      vi.mocked(instanceRepo.findAll).mockResolvedValue([]);
+
+      const result = await service.reconcileAll();
+
+      expect(result.reconciled).toBe(0);
+      expect(instanceRepo.create).not.toHaveBeenCalled();
+    });
+
+    it('does not create instances when already at desired count', async () => {
+      const server = makeServer({ id: 'srv-1', replicas: 1 });
+      vi.mocked(serverRepo.findAll).mockResolvedValue([server]);
+      vi.mocked(instanceRepo.findAll).mockResolvedValue([
+        makeInstance({ id: 'inst-1', serverId: 'srv-1', status: 'RUNNING' }),
+      ]);
+
+      const result = await service.reconcileAll();
+
+      expect(result.reconciled).toBe(0);
+      expect(instanceRepo.create).not.toHaveBeenCalled();
+    });
+
+    it('cleans up ERROR instances and creates replacements', async () => {
+      const server = makeServer({ id: 'srv-1', replicas: 1 });
+      vi.mocked(serverRepo.findAll).mockResolvedValue([server]);
+      vi.mocked(serverRepo.findById).mockResolvedValue(server);
+      vi.mocked(instanceRepo.findAll).mockResolvedValue([
+        makeInstance({ id: 'inst-dead', serverId: 'srv-1', status: 'ERROR', containerId: 'ctr-dead' }),
+      ]);
+
+      const result = await service.reconcileAll();
+
+      // Should delete ERROR instance and create a new one
+      expect(result.reconciled).toBe(1);
+      expect(instanceRepo.delete).toHaveBeenCalledWith('inst-dead');
+      expect(instanceRepo.create).toHaveBeenCalled();
+    });
+
+    it('reconciles multiple servers independently', async () => {
+      const srv1 = makeServer({ id: 'srv-1', name: 'grafana', replicas: 1, dockerImage: 'grafana:latest' });
+      const srv2 = makeServer({ id: 'srv-2', name: 'node-red', replicas: 1, dockerImage: 'nodered:latest' });
+      vi.mocked(serverRepo.findAll).mockResolvedValue([srv1, srv2]);
+      vi.mocked(serverRepo.findById).mockImplementation(async (id) => {
+        if (id === 'srv-1') return srv1;
+        if (id === 'srv-2') return srv2;
+        return null;
+      });
+      // srv-1 has a running instance, srv-2 has none
+      vi.mocked(instanceRepo.findAll).mockImplementation(async (serverId) => {
+        if (serverId === 'srv-1') return [makeInstance({ serverId: 'srv-1', status: 'RUNNING' })];
+        return [];
+      });
+
+      const result = await service.reconcileAll();
+
+      // Only srv-2 needed reconciliation
+      expect(result.reconciled).toBe(1);
+    });
+
+    it('collects errors without stopping other servers', async () => {
+      const srv1 = makeServer({ id: 'srv-1', name: 'broken', replicas: 1 });
+      const srv2 = makeServer({ id: 'srv-2', name: 'healthy', replicas: 1, dockerImage: 'img:latest' });
+      vi.mocked(serverRepo.findAll).mockResolvedValue([srv1, srv2]);
+      vi.mocked(serverRepo.findById).mockImplementation(async (id) => {
+        if (id === 'srv-2') return srv2;
+        return null; // srv-1 can't be found → will error
+      });
+      vi.mocked(instanceRepo.findAll).mockResolvedValue([]);
+
+      const result = await service.reconcileAll();
+
+      // srv-1 errored, srv-2 reconciled
+      expect(result.errors).toHaveLength(1);
+      expect(result.errors[0]).toContain('broken');
+      expect(result.reconciled).toBe(1);
+    });
+  });
 });