FIO–11561: Add Form revision MCP tools

[blakekrammes]

Summary

Adds MCP server tools for Form.io form revisions and draft/publish workflow. Closes FIO-11561.

New MCP Tools

Tool	Endpoint	Purpose
form_revisions_list	GET /form/:id/v	List published revisions as compact summaries (vid, modified, user, note); strips full form snapshot — use form_revision_get for the body
form_revision_get	GET /form/:id/v/:version	Fetch a single immutable revision by _vid or revision _id
form_revisions_set	PUT /form/:id	Set the form's revisions field. Required mode: "current" | "original" | "" — enable, switch display mode, or disable. No default — schema rejects calls without mode so the agent asks the user
form_draft_create	PUT /form/:id/draft (+ post-PUT GET /draft)	Save or overwrite the single active draft. Optional note rides as _vnote
form_draft_get	GET /form/:id/draft	Fetch the mutable active draft (_vid: "draft" row). Distinct from form_revision_get, which fetches an immutable numbered revision
form_draft_publish	PUT /form/:id	Promote the saved draft (or a caller-supplied definition) to the next published revision

Skill reference at plugin/skills/formio-api/references/project-form-revisions.md documents endpoint shapes and edge cases.

Draft _vnote Not Preserved on Publish

form_draft_publish strips _vnote from the publish body (merged draft or caller definition). Published revision's _vnote comes only from the explicit note arg.

Matches portal: draft note (WIP) and publish note (revision note) are independent. Tool + note param descriptions tell the agent to leave note undefined unless the user explicitly states the publish note.

Schema Merge (Draft → Publish)

form_draft_publish overlays only components, settings, tags, properties, display from the draft onto the current published form. Form-level fields (access, submissionAccess, revisions, owner, _id, project) always preserved from current.

Mirrors portal checkDraft() (form.js:1577-1586). Implementation: packages/mcp-server/src/tools/form-draft-merge.ts.