[Bug]: EmailActions capability not available if declarative agent has MCP action

What happened?

The EmailActions capability of declarative agent was successfully tested using a vanilla declarative agent created using ATK.

But, when an MCP Action was added to the declarative agent manifest, the agent no longer have access to the EmailActions capability.

declarativeAgent.json:

{
    "$schema": "https://developer.microsoft.com/json-schemas/copilot/declarative-agent/v1.8/schema.json",
    "version": "v1.8",
    "name": "Mailroom 95${{APP_NAME_SUFFIX}}",
    "description": "A retro email triage desk backed by Microsoft 365 Copilot email capabilities.",
    "instructions": "$[file('instruction.txt')]",
    "conversation_starters": [
       ...
    ],
    "capabilities": [
        {
            "name": "EmailActions"
        },
        {
            "name": "WebSearch"
        },
        {
            "name": "Email"
        }
    ],
    "actions": [
        {
            "id": "mailroom95_ui",
            "file": "ai-plugin.json"
        }
    ]
}

The EmailActions capability doesn't show up in the developer mode debug pane (see #28) so the assumption that the capability is missing when the MCP plugin is used comes from the fact that the agent states that it "doesn't have access to email write tools" when aksed to create an email. The email read functionality avabile through the Email capability works.

Steps to reproduce

No response

Environment

• wiqd version:
• OS:
• Node.js version:
• gh CLI version:
• Shell/Terminal:

Additional context

Logged in this repo, after discussion with @sebastienlevert.

Start with the declarativeAgent.json manifest shown in the issue and compare the EmailActions-only configuration with the version that includes the MCP action. Read the EmailActions and MCP Action documentation, then inspect the developer mode debug pane discussed in #28. Done means EmailActions remains available when the MCP plugin is present and the capability appears correctly in the debug pane.