🔧 Remove org email-invite (Node) + migration

[PierreBrisorgueil]

Phase 4 of the invitations↔org decouple epic. Plan Phase 4. Pairs with Phase 7 (Vue). Ships with its migration.

Remove all org email-invite from Node:

• organizations.membership.service.js — delete invite (L294-349), acceptInvite (L358-390), getInvite (L398) + exports; drop unused crypto; fix the dedup $in that referenced INVITED (L308).
• organizations.membershipRequest.controller.js — delete invite/acceptInvite/getInvite (L105-153) + exports.
• organizations.membershipRequest.routes.js — delete the 3 /invites* routes (L42-57).
• organizations/lib/constants.js — remove INVITED (L4).
• organizations.membership.model.mongoose.js — drop 'invited' enum (L30), inviteToken/invitedEmail/inviteExpiresAt (L33-35), sparse index (L51-53).
• delete config/templates/org-invite.html; fix the stale doc-comment in audit.middleware.js L24; rewrite organizations.lifecycle.e2e.tests.js.
• Migration modules/organizations/migrations/<ts>-drop-org-invited-memberships.js (org-owned, NOT under the optional invitations module): deleteMany({status:'invited'}), $unset the 3 fields, drop inviteToken_1 index.

Acceptance: /api/invites/* 404; no INVITED/invite refs in modules/organizations; join-requests intact.

---

🛑 Fable review corrections (2026-06-10, code-verified vs origin/master)

• Lifecycle e2e invite describe is L58-202 (a single test), NOT L58-145 — rewrite the whole describe. Re-verify ranges on origin/master (local is 115 behind; the org module's membership files are byte-identical HEAD↔origin but organizations.service.js was reworked).
• Free cleanup: REJECTED:'rejected' in lib/constants.js is dead code (rejectRequest hard-deletes; never written) — drop it.
• Stale docs to fix on removal: README.md + MIGRATIONS.md document a non-existent /members/invite path and a non-existent MembershipInvite zod schema.
• Confirmed: removed/left/rejected memberships hard-delete (no lingering doc), so the enum removal won't orphan via those paths; the migration handles the invited rows.