[plan] Add Capabilities API configuration to MCP servers

[github-actions]

Objective

Adopt the new Capabilities API from MCP Go SDK v1.1.0 to configure server behavior and disable unnecessary listChanged notifications.

Context

The MCP Go SDK v1.1.0 introduced a new Capabilities API that allows controlling server behavior. Since gh-aw's MCP tools are static (they don't change at runtime), we should disable listChanged notifications to reduce unnecessary overhead.

Approach

Update MCP server creation in two files to use ServerOptions:

File 1: pkg/cli/mcp_server.go (around line 105)

Current:

server := mcp.NewServer(&mcp.Implementation{
    Name:    "gh-aw",
    Version: GetVersion(),
}, nil)

Updated:

server := mcp.NewServer(&mcp.Implementation{
    Name:    "gh-aw",
    Version: GetVersion(),
}, &mcp.ServerOptions{
    Capabilities: &mcp.ServerCapabilities{
        ListChanged: false,  // Tools are static, no notifications needed
    },
})

File 2: pkg/gateway/gateway.go (around line 85)

Apply the same pattern to the gateway's MCP server creation.

Files to Modify

• pkg/cli/mcp_server.go - Add ServerOptions with Capabilities
• pkg/gateway/gateway.go - Add ServerOptions with Capabilities

Acceptance Criteria

• Both MCP servers use ServerOptions with ListChanged: false
• MCP server starts successfully with new configuration
• Existing tool invocations continue to work
• No listChanged notifications are sent unnecessarily
• Tests pass: make test
  Related to [plan] Adopt MCP Go SDK v1.1.0 improvements #6249

AI generated by Plan Command for discussion #6222