Add upstream-shaped scoped introspection plugin

.gitignore

@@ -13,6 +13,7 @@ postgres/pgsql-test/output/
 .env.local
 graphql/server/logs/
 graphql/server/*.heapsnapshot
+packages/perf-harness/artifacts/
 
 # Ephemeral pgpm modules installed by `pnpm fixtures:install` (pgpm install)
 /extensions/

eslint.config.mjs

@@ -20,6 +20,8 @@ export default [
       '**/*.generated.ts',
       'postgres/pg-ast/src/asts.ts',
       'postgres/pg-ast/src/wrapped.ts',
+      // upstream-derived source; preserve Crystal formatting for reviewability
+      'graphile/graphile-scoped-introspection/src/upstream/**',
       // read verbatim at codegen time and written into generated clients
       'graphql/codegen/src/core/codegen/templates/**',
       // codegen output snapshots and standalone sqitch/pgpm fixture projects

graphile/graphile-scoped-introspection/README.md

@@ -0,0 +1,21 @@
+# graphile-scoped-introspection
+
+CNC-owned, upstream-shaped PostgreSQL introspection plugin. The package starts
+from the published Graphile implementations that own the two relevant seams:
+
+- `pg-introspection@1.0.1` query generation and result augmentation;
+- `graphile-build-pg@5.1.3` `PgIntrospectionPlugin` orchestration.
+
+The copied source is kept together so scoped changes remain reviewable against
+the upstream package boundaries. See `UPSTREAM.md` and `UPSTREAM_LICENSE.md` for
+provenance and licensing.
+
+`ScopedIntrospectionPreset` atomically disables the stock
+`PgIntrospectionPlugin` and installs `PgScopedIntrospectionPlugin`. The
+replacement preserves the stock query unless `gather.pgScopedIntrospection`
+contains an entry for the PG service name. Scoped services use a parameterized
+catalog query, validate required and allowed namespaces after parsing, and can
+apply dependency-closure validation to retained PostgreSQL types.
+
+Installing this package alone does not change Graphile's default preset or any
+PG service. CNC owns the configuration that selects and installs the preset.

graphile/graphile-scoped-introspection/UPSTREAM.md

@@ -0,0 +1,31 @@
+# Upstream provenance
+
+The files under `src/upstream/pg-introspection` and
+`src/upstream/graphile-build-pg` are derived from the MIT-licensed Graphile
+Crystal repository at commit:
+
+`fb9792dd4e64601530026d1ec4079652a4f33c1c`
+
+That commit publishes `pg-introspection@1.0.1` and
+`graphile-build-pg@5.1.3`, matching the versions pinned by CNC.
+
+Copied paths:
+
+- `utils/pg-introspection/src/*.ts`
+- `graphile-build/graphile-build-pg/src/plugins/PgIntrospectionPlugin.ts`
+- `graphile-build/graphile-build-pg/src/version.ts`
+- `graphile-build/graphile-build-pg/src/watchFixtures.ts`
+
+The baseline copy has only the integration adaptations needed to compile the
+published sources as an isolated CNC package:
+
+- relative imports and TypeScript extension syntax match the CNC package layout;
+- the published `graphile-build-pg` declarations are loaded for registry and
+  service types that the original monorepo supplied through its compilation
+  unit (including the standard PG adaptor), and its public
+  `pg-introspection` types remain the plugin contract;
+- Crystal's `useUnknownInCatchVariables: false` setting is retained; and
+- one otherwise-contextual `description` value has an explicit type annotation.
+
+Functional changes are layered in separate commits. The copied source keeps its
+upstream formatting so future comparisons remain useful.

graphile/graphile-scoped-introspection/UPSTREAM_LICENSE.md

@@ -0,0 +1,21 @@
+## The MIT License (MIT)
+
+Copyright © `2025` Benjie Gillam
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of
+this software and associated documentation files (the “Software”), to deal in
+the Software without restriction, including without limitation the rights to
+use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
+the Software, and to permit persons to whom the Software is furnished to do so,
+subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.