[Improve] Expose deployment MCP tools directly in Fast

[roomote-roomote]

​Opened on behalf of @daniel-lxs. Follow up by mentioning @roomote-roomote or in the web UI.

What changed

Fast now mounts each actor-authorized deployment MCP server through a local authenticated MCP bridge, so its tools appear individually under their server prefixes with their upstream JSON schemas intact. Calls continue through Fast's existing broker for allowlist revalidation, per-turn deduplication, acknowledgement gating, short-lived deployment-proxy token refresh, and durable auditing.

The generic integration_call tool and its prompt contract were removed. Fast guidance now references the first-class Roomote MCP tools directly, while advisor and judge subagents retain deployment MCP access without gaining custom automation management or parent-only Fast tools. Fast injects its Slack or Discord conversation provider into those first-class Roomote chat tools, preserving raw channel ID, name, mention, and link support.

Why this change was made

Fast previously wrapped the actor-resolved MCP catalog in one generic tool whose schema hid every upstream tool contract from the model. Direct MCP mounting brings Fast in line with sandboxed delegated tasks without bypassing the policy and audit boundary introduced in #1604.

Impact

Fast agents can select deployment MCP tools as normal first-class tools with native argument schemas. Existing actor authorization, deployment-disabled tool filtering, per-user isolation, acknowledgement requirements, duplicate-call protection, custom-automation restrictions, integration audit records, and provider-aware chat lookups remain in effect.

[roomote-community]

No new code issues found. See task

_{Reviewed 952ec95}

[roomote-roomote]

Synced onto develop and resolved all stacked conflicts in 952ec959, preserving first-class deployment MCP tools plus provider-aware current-channel lookups, parent-only custom automation management, and all-repositories launches. Validation passed: 105 focused Fast/OpenCode tests, @roomote/cloud-agents and @roomote/api TypeScript checks, and the full pre-push gate. The current-head review reports no code issues, with no review threads or checklist items outstanding.