Enable/disable MCP servers per roo mode (e.g., code, debug, ask)

[sanathusk]

Add the ability to enable or disable individual MCP servers at the room-mode level.

Motivation:

I often feel that i don't need a particular mcp enabled while useing aspecifc roomode.Allowing each mode to selectively enable specific MCP servers (e.g., Chrome MCP only in code & debugging modes, disabled in ask mode) would reduce token usage and avoid unnecessary external calls when a capability isn’t needed.

Proposed behavior:

• Per-mode settings to toggle each available MCP server (on/off).
• Settings inherited from a global default but overridable per room mode.

Benefits:

Token and cost savings.
Reduced latency and fewer unnecessary external service calls.
Better control and safety for restricted modes.