test(vitest): Add type assertions to mockImplementation calls

Add 'as any' type assertions to mockImplementation calls to fix Vitest v4 constructor compatibility.

This resolves the error: "() => mockServer is not a constructor"

The assertions are necessary because Vitest v4 changed how mock constructors work.
Added biome-ignore comments to document why 'any' is required.

Author: yamadashy

tests/mcp/mcpServer.test.ts

@@ -85,7 +85,8 @@ describe('MCP Server', () => {
         ...createMockServerProps(),
       } as unknown as McpServer;
 
-      vi.mocked(McpServer).mockImplementation(() => mockMcpServer);
+      // biome-ignore lint/suspicious/noExplicitAny: Vitest v4 requires any for constructor mocks
+      vi.mocked(McpServer).mockImplementation(() => mockMcpServer as any);
       try {
         await runMcpServer({ processExit: mockExit });
       } catch (e) {
@@ -107,7 +108,8 @@ describe('MCP Server', () => {
         ...createMockServerProps(),
       } as unknown as McpServer;
 
-      vi.mocked(McpServer).mockImplementation(() => mockServer);
+      // biome-ignore lint/suspicious/noExplicitAny: Vitest v4 requires any for constructor mocks
+      vi.mocked(McpServer).mockImplementation(() => mockServer as any);
       await expect(runMcpServer({ processExit: mockExit })).resolves.toBeUndefined();
       mockLogger.trace.mockClear();
       process.emit('SIGINT');
@@ -131,7 +133,8 @@ describe('MCP Server', () => {
         ...createMockServerProps(),
       } as unknown as McpServer;
 
-      vi.mocked(McpServer).mockImplementation(() => mockServer);
+      // biome-ignore lint/suspicious/noExplicitAny: Vitest v4 requires any for constructor mocks
+      vi.mocked(McpServer).mockImplementation(() => mockServer as any);
       await expect(runMcpServer({ processExit: mockExit })).resolves.toBeUndefined();
       mockLogger.trace.mockClear();
       process.emit('SIGTERM');
@@ -156,7 +159,8 @@ describe('MCP Server', () => {
         ...createMockServerProps(),
       } as unknown as McpServer;
 
-      vi.mocked(McpServer).mockImplementation(() => mockServer);
+      // biome-ignore lint/suspicious/noExplicitAny: Vitest v4 requires any for constructor mocks
+      vi.mocked(McpServer).mockImplementation(() => mockServer as any);
       await expect(runMcpServer({ processExit: mockExit })).resolves.toBeUndefined();
       mockLogger.error.mockClear();
       process.emit('SIGINT');