Missing update_*_note / delete_*_note tools (and expose note global ID in list_*_note)

[Hakihiro]

Problem

The MCP server exposes add_*_note and list_*_note for epics/issues/MRs, but no update_*_note or delete_*_note. When a note needs to be rewritten (wrong language, typo, outdated info) or removed, callers must drop back to raw glab api graphql with the updateNote / destroyNote mutations — breaking the MCP-first contract.

Concretely encountered during an internal cleanup session on 2026-04-20: 8 notes posted in French had to be rewritten in English (per project convention). Each correction required a manual GraphQL fallback.

A related limitation: list_*_note responses currently don't include the note's global ID. Even if update_*_note / delete_*_note shipped today, a caller couldn't identify which note to target from the list output (only author, body, createdAt are visible).

Proposal

Two coordinated changes:

1. Add the missing tools (thin wrappers over existing GraphQL mutations):

Tool	GraphQL mutation
update_epic_note, update_issue_note, update_mr_note	updateNote(input: { id, body })
delete_epic_note, delete_issue_note, delete_mr_note	destroyNote(input: { id })

Input shape: the note global ID (e.g. gid://gitlab/Note/12345) + body for updates.

2. Expose the note global ID in list_*_note

Add the id field to the list output so callers can feed it straight into the new update/delete tools.

Why this matters

• MCP-first workflows break as soon as a note correction is needed — currently the only recourse is raw GraphQL with hand-built payloads.
• Note correction is a routine operation, not an edge case (language conventions, typos, updating status summaries as work progresses).
• Both mutations already exist server-side; this is purely wrapper surface area.

Effort

Low. Both mutations are thin wrappers; exposing id in the list output is a single additional field in the existing query.

[Hakihiro]

Implemented — all 6 note tools added (update_issue_note, delete_issue_note, update_epic_note, delete_epic_note, update_mr_note, delete_mr_note) and list_*_notes now expose the global note ID.