chore(mgmt teardown step 5+6): drop stale dokploy comment + append DONE log

Per docs/plans/mgmt-teardown.md §4 steps 5 + 6.

Step 5: deploy/dokploy.yaml — stale "federated with mgmt.msbls.de" line
in the header comment replaced with the current host-scoped /login cookie
model. The mgmt federation never happened in projax anyway (projax
cookies are host-scoped, no Domain attribute).

Step 6: append a "DONE 2026-05-16" section to docs/plans/mgmt-teardown.md
recording every step's commit hash across both repos, the head-approved
deviation from §4 step 1 (SvelteKit-side redirect instead of Dokploy
Traefik labels — Dokploy config is UI-only), verification curls, and the
post-teardown janitorial that's out of scope for the worker (env-var
cleanup in Dokploy, DNS at m's leisure).

m/msbls.de side merged separately (86bfa61) — three commits:
2941dc4 (redirect), <previous step's commit covers the rest>.

deploy/dokploy.yaml

@@ -2,8 +2,8 @@
 #
 # Apply via Dokploy UI on mlake, or as a reference for the manual setup.
 # Public over HTTPS with Let's Encrypt; auth is enforced at the application
-# layer via Supabase JWT cookies federated with mgmt.msbls.de.
-# Single replica, single tenant (m).
+# layer via Supabase JWT cookies set by projax's own /login (host-scoped,
+# no Domain attribute). Single replica, single tenant (m).
 #
 # Environment expected (set via Dokploy secrets, NEVER commit):
 #   PROJAX_DB_URL        postgres://projax_admin:<pw>@<msupabase-tailscale-ip>:6789/postgres?sslmode=disable