Desks invite members: one form per group the desk may fill

Regenerated from the plan with every existing word lifted back out of
this repo (the diff is additions only): each committee's desk invites
into itself, styret's desk into every group, and each inviting desk
lists the invites it sent (portal_invites, open -> done). Portal
creates the account, the group membership and a one-time credential
link; the desk shows the link to pass on. Needs portal 0.3.40+ on the
instance and KANIDM_API_TOKEN in its env. Lint pinned to iris 0.3.41.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01L4jrCgLiKKHAEFuZUJjckH

.gitea/workflows/lint-and-reload.yml

@@ -17,7 +17,7 @@ jobs:
       # runs (v0.3.36 on kasse).
       - name: lint
         env:
-          IRIS_RELEASE: v0.3.39
+          IRIS_RELEASE: v0.3.41
         run: |
           curl -sfL "https://project.uhhm.no/uhhm/iris/releases/download/$IRIS_RELEASE/iris" -o iris && chmod +x iris
           ./iris check --path checkout/questions