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/20260714120400_performance_indexes.sql

@@ -0,0 +1,33 @@
+-- Performance indexes (spec §15).
+--
+-- Existing indexes already cover employees(team_id/division_id/manager_id/
+-- status), employee_history(employee_id, event_date desc), positions(team_id/
+-- status), audit_log(occurred_at desc), and the new pending_org_changes
+-- table's own indexes (see its migration). This adds the gaps: location-based
+-- filtering, entry/exit date range queries (dashboard "upcoming" widget +
+-- Eintritte/Austritte reports), personnel-number lookup (also enforces the
+-- uniqueness a personnel number should have, which the identity column
+-- alone did not), reorg/audit foreign-key lookups, and trigram search
+-- support for the employee list's free-text search box.
+
+create unique index if not exists idx_employees_personnel_number on employees (personnel_number);
+create index if not exists idx_employees_location_id on employees (location_id);
+create index if not exists idx_employees_entry_date on employees (entry_date);
+create index if not exists idx_employees_exit_date on employees (exit_date) where exit_date is not null;
+create index if not exists idx_employees_karenz_return_date on employees (karenz_return_date) where karenz_return_date is not null;
+
+create index if not exists idx_audit_log_target_employee_id on audit_log (target_employee_id) where target_employee_id is not null;
+create index if not exists idx_employee_history_reorg_scenario_id on employee_history (reorg_scenario_id) where reorg_scenario_id is not null;
+create index if not exists idx_employee_history_event_type on employee_history (event_type);
+create index if not exists idx_reorg_scenarios_applied on reorg_scenarios (applied, applied_at desc);
+create index if not exists idx_positions_division_id on positions (division_id);
+
+-- Free-text search over name/title (Mitarbeiter:innen list search box) —
+-- trigram index so ILIKE '%term%' queries can use an index instead of a
+-- sequential scan.
+create extension if not exists pg_trgm;
+
+create index if not exists idx_employees_name_trgm
+  on employees using gin ((first_name || ' ' || last_name) gin_trgm_ops);
+create index if not exists idx_employees_job_title_trgm
+  on employees using gin (job_title gin_trgm_ops);