[AI] Add Yarn constraints to enforce consistent dependency versions (#7229)

* [AI] Add yarn constraints to enforce consistent dependency versions

Adds a `yarn.config.cjs` that uses Yarn 4's built-in constraints feature
to detect when the same dependency is declared with different version
ranges across workspaces. Workspace protocol references and
peerDependencies are excluded from the check.

Also adds a `yarn constraints` convenience script and the `@yarnpkg/types`
dev dependency for type-checked constraint authoring.

https://claude.ai/code/session_01B1xRjZXn6b18anZjo8cbqb

* Add release notes for PR #7229

* Add constraints job to GitHub Actions workflow

* Fix constraints

---------

Co-authored-by: Claude <noreply@anthropic.com>
Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>

yarn.config.cjs

@@ -0,0 +1,54 @@
+// @ts-check
+
+/** @type {import('@yarnpkg/types')} */
+const { defineConfig } = require('@yarnpkg/types');
+
+/**
+ * Enforce that all workspaces use the same version of any shared dependency.
+ * Workspace protocol references (workspace:*) and peerDependencies are
+ * excluded since they intentionally use different/wider ranges.
+ *
+ * @param {import('@yarnpkg/types').Yarn.Constraints.Context} context
+ */
+function enforceConsistentDependencies({ Yarn }) {
+  /** @type {Map<string, Map<string, Array<import('@yarnpkg/types').Yarn.Constraints.Workspace>>>} */
+  const dependencyVersions = new Map();
+
+  for (const workspace of Yarn.workspaces()) {
+    for (const type of ['dependencies', 'devDependencies']) {
+      for (const dep of Yarn.dependencies({ workspace, type })) {
+        if (dep.range.startsWith('workspace:')) continue;
+
+        if (!dependencyVersions.has(dep.ident)) {
+          dependencyVersions.set(dep.ident, new Map());
+        }
+        const versions = dependencyVersions.get(dep.ident);
+        if (!versions.has(dep.range)) {
+          versions.set(dep.range, []);
+        }
+        versions.get(dep.range).push(workspace);
+      }
+    }
+  }
+
+  for (const [ident, versions] of dependencyVersions) {
+    if (versions.size <= 1) continue;
+
+    const rangeList = [...versions.keys()].join(', ');
+
+    for (const [, workspaces] of versions) {
+      for (const workspace of workspaces) {
+        workspace.error(
+          `Package "${ident}" has inconsistent versions across workspaces (${rangeList}). ` +
+            `All workspaces must use the same version range.`,
+        );
+      }
+    }
+  }
+}
+
+module.exports = defineConfig({
+  async constraints(ctx) {
+    enforceConsistentDependencies(ctx);
+  },
+});