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/20260714120500_default_grants.sql

@@ -0,0 +1,25 @@
+-- Explicit schema/table/sequence/routine grants for anon/authenticated/
+-- service_role.
+--
+-- Found while standing up a local Supabase instance to run the integration
+-- test suite (spec §17): every table in this schema
+-- relies on RLS policies to restrict access, but RLS only ever *narrows*
+-- what an already-GRANTed role may do — Postgres still checks ordinary
+-- object privileges first, independent of a role's BYPASSRLS flag. On
+-- Supabase's hosted platform this GRANT setup is applied automatically
+-- during project provisioning, so it was invisible here: every previous
+-- migration worked fine against the already-provisioned hosted project, but
+-- the exact same migrations against a *fresh* Postgres (a new local dev
+-- instance, a disaster-recovery restore, or CI) fail with "permission
+-- denied for table X" even for the service role, since that grant was never
+-- actually part of this repo's own migrations. Making it explicit here
+-- makes the schema fully self-contained and reprovisionable from scratch.
+grant usage on schema public to anon, authenticated, service_role;
+
+grant all on all tables in schema public to anon, authenticated, service_role;
+grant all on all sequences in schema public to anon, authenticated, service_role;
+grant all on all routines in schema public to anon, authenticated, service_role;
+
+alter default privileges in schema public grant all on tables to anon, authenticated, service_role;
+alter default privileges in schema public grant all on sequences to anon, authenticated, service_role;
+alter default privileges in schema public grant all on routines to anon, authenticated, service_role;