Add Microsoft Graph draft, reply, and file attachment flows

[erik-kroon]

Applications that compose mail through Microsoft Graph drafts currently hit the unsupported-route fallback when creating a message or reply. This adds the JSON draft lifecycle so clients can create a draft, update it, attach files, send it, and read the saved message and attachment bytes through the existing Graph surface.

• Add draft creation, draft PATCH, createReply, and send, with delegated scopes and mailbox ownership checks. Sending returns an empty 202 and moves the same message into sent items; replies retain the original conversation and respect replyTo.
• Persist file attachments supplied during draft creation or through the attachment endpoint, with list, metadata, and raw-byte reads. Validate base64 and the simple attachment size limit before mutation. Inline-only files do not set hasAttachments.
• Record mutations in the request ledger, advertise operations in the manifest/OpenAPI, and update the README, service docs, agent skill and CLI help.
• Cover compose/reply sequences, binary round trips, Bcc retention, cross-mailbox access, scope failures, injected send failures, invalid input, size boundaries and concurrent draft edits with nine integration tests.

The manifest marks limited operations as partial. This deliberately supports delegated /me JSON mail with file attachments smaller than 3 MB. MIME, upload sessions, item/reference attachments, generated quoted reply bodies, mail-folder/user-scoped routes and external delivery are outside this change. IDs remain stable even without the immutable-ID preference; default Outlook ID changes are not simulated.

Validation:

• pnpm install --frozen-lockfile
• pnpm exec turbo run build --concurrency=3 (29 successful tasks)
• pnpm format:check and node scripts/sync-versions.mjs --check
• pnpm exec turbo run type-check lint test --concurrency=3 (92 successful tasks)
• After the final concurrency fix: pnpm exec turbo run build type-check lint test --filter=@emulators/microsoft --concurrency=2 (57 Microsoft tests passed; three existing live tests skipped)
• Microsoft Graph PHP SDK v2.46.0 against a separately running local emulator: compose, reply, attachment POST, send, attachment JSON decoding and raw download passed. This used synthetic credentials and no external provider calls.

No live Microsoft validation was performed. Relevant API contracts: create draft, create reply, add attachment, send draft.