refactor(typescript): wire the testmu provider into the reference graph

Rebase overlap with #3118: provider-testmu entered the workspace as the 26th
package after this branch's lists were derived. It gets the same treatment as
every other package - manifest-derived references and a per-project
tsBuildInfoFile - plus entries in the root and examples/sdk reference lists,
which the guard test now proves complete again.

Its dependency on the root agent-device package is the first edge that has no
composite project to point at: the root tsconfig is a noEmit entry point and
TS6310 forbids referencing it, so that import type-resolves through the
package's own paths mapping. The guard test encodes exactly that: root-named
workspace deps drop out of the references equality and must instead have a
paths mapping, or the test fails.

Author: thymikee

examples/sdk/tsconfig.json

@@ -50,6 +50,7 @@
     { "path": "../../packages/platform-vega" },
     { "path": "../../packages/platform-web" },
     { "path": "../../packages/provider-limrun" },
+    { "path": "../../packages/provider-testmu" },
     { "path": "../../packages/provider-webdriver" },
     { "path": "../../packages/provision-kit" },
     { "path": "../../packages/proxy" },

packages/provider-testmu/tsconfig.json

@@ -6,11 +6,17 @@
     "emitDeclarationOnly": true,
     "declaration": true,
     "declarationDir": "./dist-types",
+    "tsBuildInfoFile": "./dist-types/.tsbuildinfo",
     "rootDir": "./src",
     "paths": {
       "agent-device/plugins": ["./node_modules/agent-device/src/sdk/plugins.ts"],
       "agent-device/plugins/webdriver": ["./node_modules/agent-device/src/sdk/plugin-webdriver.ts"]
     }
   },
-  "include": ["src"]
+  "include": ["src"],
+  "references": [
+    { "path": "../contracts" },
+    { "path": "../kernel" },
+    { "path": "../provider-webdriver" }
+  ]
 }

scripts/layering/project-references.test.ts

@@ -15,11 +15,24 @@ import { readWorkspacePackages } from './package-boundaries.ts';
 const repoRoot = path.resolve(import.meta.dirname, '../..');
 
 /** tsconfig JSONC minus line comments; both comment-bearing files use `//` only. */
-function readTsconfig(relativePath: string): { references?: { path: string }[] } {
+function readTsconfig(relativePath: string): {
+  references?: { path: string }[];
+  extends?: string;
+  compilerOptions?: Record<string, unknown>;
+} {
   const source = fs.readFileSync(path.join(repoRoot, relativePath), 'utf8');
   return JSON.parse(source.replaceAll(/^\s*\/\/.*$/gm, ''));
 }
 
+/**
+ * The published root package name. It names no composite project: the root tsconfig is a
+ * noEmit entry point TS6310 forbids referencing, so a workspace dependency on it is
+ * type-resolved through tsconfig `paths`, never through a reference edge.
+ */
+const rootPackageName = (
+  JSON.parse(fs.readFileSync(path.join(repoRoot, 'package.json'), 'utf8')) as { name: string }
+).name;
+
 /** Repo-relative package dir for one `references[].path` entry, resolved from its project. */
 function referencedPackageDirs(tsconfigFile: string, projectDir: string): string[] {
   const config = readTsconfig(tsconfigFile);
@@ -86,6 +99,10 @@ test('every package tsconfig references exactly its manifest workspace dependenc
   // references are DERIVED from the manifest DAG, so an import a manifest gains must add the
   // matching reference (edge freshness, which tsc -b never asks for) and a removed one must
   // drop it (an extra reference hides a stale edge that tsc -b tolerates silently).
+  // The one expressible-edge exception: a workspace dependency on the ROOT package
+  // (`agent-device`) has no composite project to point at (TS6310). Those imports are
+  // type-resolved through tsconfig `paths`, so the dependency is asserted present in
+  // paths instead of references.
   const packages = readWorkspacePackages(repoRoot);
   const nameByDir = new Map(packages.map((pkg) => [pkg.dir, pkg.name]));
   for (const pkg of packages) {
@@ -98,8 +115,17 @@ test('every package tsconfig references exactly its manifest workspace dependenc
     }
     assert.deepEqual(
       referencedDirs.map((dir) => nameByDir.get(dir)),
-      [...pkg.workspaceDependencies].sort(),
+      [...pkg.workspaceDependencies].filter((name) => name !== rootPackageName).sort(),
       `${pkg.dir}/tsconfig.json references must equal its manifest workspace:* dependencies`,
     );
+    if (pkg.workspaceDependencies.has(rootPackageName)) {
+      const config = readTsconfig(`${pkg.dir}/tsconfig.json`);
+      const paths = (config.compilerOptions?.paths ?? {}) as Record<string, unknown>;
+      assert.ok(
+        Object.keys(paths).some((key) => key.startsWith(`${rootPackageName}/`)),
+        `${pkg.dir} depends on the root package without a paths mapping; tsc cannot ` +
+          'resolve it (the root project cannot be referenced)',
+      );
+    }
   }
 });