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>

lib/db/pool.ts

@@ -7,7 +7,7 @@ import { Pool, types } from "pg";
 // Typprüfer und keiner der Tests fangen konnte.
 //
 // Die alte API-Schicht lieferte JSON: ein `date` kam als "2026-08-03" an,
-// ein `numeric` als Zahl. Genau so steht es in lib/supabase/types.ts, und
+// ein `numeric` als Zahl. Genau so steht es in lib/types.ts, und
 // darauf baut die gesamte Anwendung — Sortierungen mit localeCompare,
 // Vergleiche wie `entry_date <= stichtag`, das Ableiten des Status.
 //
@@ -88,7 +88,7 @@ export function getPool(): Pool {
     statement_timeout: 20_000,
     idle_in_transaction_session_timeout: 20_000,
     connectionTimeoutMillis: 10_000,
-    // Verwaltete Anbieter (Azure, RDS, Supabase) verlangen TLS; lokal nicht.
+    // Verwaltete Anbieter (Azure, RDS) verlangen TLS; im eigenen Netz nicht.
     ssl: process.env.DATABASE_SSL === "false" ? undefined : { rejectUnauthorized: false },
   });