feat: add module schema discovery and validation

tests/boundaries.test.ts

@@ -29,6 +29,7 @@ describe("repository dependency boundaries", () => {
     ["module-imports-surface", "modules-use-public-platform-contracts"],
     ["package-boundary-direction", "modules-use-public-platform-contracts"],
     ["cross-module-import", "modules-do-not-import-other-modules"],
+    ["module-schema-imports-module", "modules-do-not-import-other-modules"],
     ["surface-imports-module", "surfaces-use-public-contracts"],
     ["cross-surface-import", "surfaces-are-independent"],
     ["builder-imports-module", "builder-composes-contracts"],

tests/fixtures/boundaries/module-schema-imports-module/modules/calendar/src/schema.ts

@@ -0,0 +1,3 @@
+import { peopleRecords } from "../../../modules/people/src/schema.js";
+
+export const invalidPrivateSchemaImport = peopleRecords;

tests/fixtures/boundaries/module-schema-imports-module/modules/people/src/schema.ts

@@ -0,0 +1 @@
+export const peopleRecords = "private people schema";