Remove Supabase

The database moved to a container of our own; the platform is gone.
This takes out what was left of it — and, where the leftovers were load
bearing, moves rather than deletes.

Moved, not deleted:

  supabase/migrations/  -> db/migrations/      the schema's source of truth
  supabase/build-org.ts -> scripts/build-org.ts
  lib/supabase/types.ts -> lib/types.ts        52 import sites repointed

The bookkeeping needed care. It lived in `supabase_migrations.schema_migrations`,
and simply renaming the schema would have left the runner facing an empty
table: it would have called all 67 migrations pending and replayed them
against a database that is long since current. So the runner now creates
`migrationen.schema_migrations` and, once, copies the old rows across —
guarded so a second run does nothing and a fresh database skips it entirely.
Only then does migration 20260907100000 drop the old schema.

Deleted: the CLI config, the seed, the historical schema/function dumps
(nothing read them), scripts/umzug-von-supabase.sh (the move is done), and
both Supabase packages plus the CLI. Nothing in the application imported
them — the build now succeeds with no environment variables at all, which
is the proof.

Integration tests: six of them signed in through Supabase Auth and asserted
against the anon key and the service role. That model is gone, so the tests
were not portable — they are deleted. session-context and
employee-status-filter already ran on pg and are untouched; om-reporting is
ported to a direct connection because it guards a real risk (the reporting
line rule exists twice, once in SQL and once in TypeScript).

CI: the integration job started a Supabase stack. It now runs a postgres
service, applies deploy/db-init and every migration to an empty database —
that was the valuable part, and it still holds — then checks that a second
run is a no-op, which is what proves the bookkeeping works.

Docs: security-review.md audited a service-role key, a cookie adapter and
auth.users, none of which exist. Restating findings about removed components
would suggest today's system had been reviewed; it has not. It now records
what was removed and says a fresh review is due. data-model.md was already
marked obsolete and described the pre-OM schema; azure-migration.md was a
plan for a route not taken. Both deleted.

Verified: npm ci, typecheck, lint, 445 tests, build — all clean without the
packages. Integration tests skip cleanly with no database. Migration SQL and
the runner are reviewed but NOT executed: no Docker here, and the old
instance no longer resolves.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

db/migrations/20260601000300_start_karenz_function.sql

@@ -0,0 +1,29 @@
+-- Addendum to supabase/functions.sql — run after that file.
+--
+-- The spec's "Karenz verwalten" panel (§4.5) only covers employees already on
+-- Karenz (adjust return date / record return). It doesn't specify the fields
+-- for *starting* a Karenz period from Aktiv, even though §4.3 clearly shows a
+-- "Karenz" button for that case. This fills that gap with a reasonable,
+-- minimal form: start date + planned return date + optional note.
+
+create or replace function start_karenz(payload jsonb)
+returns void language plpgsql as $$
+declare
+  v_employee_id uuid := (payload->>'employee_id')::uuid;
+  v_name text;
+begin
+  perform require_hr_admin();
+  select first_name || ' ' || last_name into v_name from employees where id = v_employee_id;
+
+  update employees set status = 'Karenz', karenz_return_date = (payload->>'planned_return_date')::date
+    where id = v_employee_id;
+
+  insert into employee_history (employee_id, event_date, event_type, description)
+    values (v_employee_id, (payload->>'karenz_start_date')::date, 'Karenz',
+      'Karenzantritt, geplante Rückkehr am ' || (payload->>'planned_return_date') ||
+      case when payload->>'note' is not null and payload->>'note' <> '' then ' — ' || (payload->>'note') else '' end);
+
+  insert into audit_log (actor_user_id, actor_name, action, target_label, target_employee_id, details)
+    values (auth.uid(), current_actor_name(), 'Karenz', v_name, v_employee_id, 'Karenzantritt, geplante Rückkehr ' || (payload->>'planned_return_date'));
+end;
+$$;