ci: probe the server's SQL against a Postgres service

Nothing in CI ran a statement against anything but SQLite, so the claim
that the dialect layer keeps the repositories portable was never measured
and new SQLite-only SQL could land unseen. The new postgres-probe job
(server/scripts/pg-probe.ts, npm run probe:pg) does that against a
postgres:17 service container:

- it derives a Postgres schema from the entities with MikroORM's schema
  generator, keeping TEXT timestamps, mapping the SQLite-only defaults and
  the NOCASE collation, and leaving foreign keys out;
- it runs every dialect helper on an in-memory SQLite and on Postgres
  against the same expectation, and every case has to pass;
- it calls every public repository method once with arguments the
  TypeScript checker builds from the parameter types, through a Postgres
  driver that runs each statement alone in a rolled-back transaction with
  a statement timeout and records whether Postgres accepted it.

The statements Postgres refuses are held per method to
scripts/pg-probe-baseline.json, which may only shrink. The baseline starts
unmeasured (failing: null): the job reports, passes and uploads the first
measurement as the pg-probe-baseline artifact, together with a JSON report,
so the commit that seeds it and every later commit that lowers it needs no
local Postgres. The probe refuses a database holding tables it did not
create.

@mikro-orm/postgresql joins the server's devDependencies at the 7.2.1 the
other MikroORM packages resolve to; the image's production install leaves
it out. The job needs the preflight gates like every test job, runs only
for the code area, stops after ten minutes and is part of ci-ok.

CLAUDE.md

@@ -44,6 +44,7 @@ cd client && npm run lint:skips                    # no .only; skipped tests may
 cd client && npm run lint:i18n-keys                # every key the client names exists in en (CI gate)
 cd server && npm run lint:boundaries               # no new import cycles or cross-domain reach-ins (CI gate)
 cd server && npm run lint:dialect                  # SQLite-only SQL spellings may only shrink (CI gate; rules in server/CLAUDE.md)
+cd server && npm run probe:pg                      # dialect helpers + every repository statement against Postgres (CI job; needs TREK_PG_PROBE_URL)
 cd client && npm run theme:lint                    # flag styling that bypasses appearance tokens (local only)
 npm run typecheck --workspace=server               # tsc --noEmit (also client/shared; server also has typecheck:tests)
 ```
@@ -118,7 +119,7 @@ These principles come out of a full-repo audit and shape all new code:
 
 ## Quality gates in CI
 
-`.github/workflows/test.yml` runs, per package: typecheck (server also `typecheck:tests`), lint (client through `lint:warnings`, which also holds the warning count per rule), `lint:pages`, `lint:rtl`, `lint:size` (client and server), the server's `lint:boundaries`, the client's `lint:format`, `lint:layers`, `lint:offline`, `lint:skips` and `lint:i18n-keys`, shared's `contracts:open`, `check:plugin-facts`, `i18n:parity:strict` (with the untranslated-strings ratchet), the S3 contract suite, the browser end-to-end flows (Chromium and WebKit), a client build with `check:gl-split`, coverage for all four packages, then a SonarCloud scan. It also builds the Docker image and boots it until `/api/health/ready` answers (`docker-image`), and lints and renders the Helm chart against the Kubernetes schemas and runs `docker compose config` on every compose file (`deploy-manifests`). `lint-prettier.yml` additionally runs `lint` + `format:check` on `shared/`. `plugin-sdk` has no lint script and is outside the eslint gates. **Not in CI**: `theme:lint` and the screenshot and help-media Playwright projects; run them locally. There are no git hooks; nothing runs before a commit except you. Other workflows build Docker images, scan them, and publish `trek-plugin-sdk` on `plugin-sdk-v*` tags.
+`.github/workflows/test.yml` runs, per package: typecheck (server also `typecheck:tests`), lint (client through `lint:warnings`, which also holds the warning count per rule), `lint:pages`, `lint:rtl`, `lint:size` (client and server), the server's `lint:boundaries`, the client's `lint:format`, `lint:layers`, `lint:offline`, `lint:skips` and `lint:i18n-keys`, shared's `contracts:open`, `check:plugin-facts`, `i18n:parity:strict` (with the untranslated-strings ratchet), the S3 contract suite, the Postgres probe (`postgres-probe`: every dialect helper on SQLite and Postgres, and every repository statement against a Postgres service, held to a baseline that only shrinks; see `server/CLAUDE.md`), the browser end-to-end flows (Chromium and WebKit), a client build with `check:gl-split`, coverage for all four packages, then a SonarCloud scan. It also builds the Docker image and boots it until `/api/health/ready` answers (`docker-image`), and lints and renders the Helm chart against the Kubernetes schemas and runs `docker compose config` on every compose file (`deploy-manifests`). `lint-prettier.yml` additionally runs `lint` + `format:check` on `shared/`. `plugin-sdk` has no lint script and is outside the eslint gates. **Not in CI**: `theme:lint` and the screenshot and help-media Playwright projects; run them locally. There are no git hooks; nothing runs before a commit except you. Other workflows build Docker images, scan them, and publish `trek-plugin-sdk` on `plugin-sdk-v*` tags.
 
 - **`ci-ok` is the required check.** The branch ruleset requires `ci-ok` (plus `lint` and `check-target` from their own workflows), and `ci-ok` needs every job above except the scan. It fails if any of them failed or was cancelled and passes if they passed or were skipped. A new gate job counts only once it is listed in `ci-ok`'s `needs:`.
 - **What runs is decided by `changes`, not by `on.paths`**: `scripts/ci/changed-areas.mjs` maps the changed files to the `code`, `image` and `deploy` areas (tests: `npm run test:ci-scripts`). A path filter on the workflow would leave `ci-ok` unreported on a docs-only PR and block it. Add a new top-level file the build reads to the right area there.