Trial ADR-backed component review rules

.github/instructions/component-review.instructions.md

@@ -0,0 +1,43 @@
+---
+applyTo: 'packages/react/src/**/*'
+---
+
+# ADR-backed component review trial
+
+Apply these rules only to behavior or contracts introduced or expanded by the
+change. Report concrete impact, cite the rule ID, and do not report pre-existing
+migration debt.
+
+## `component-review.children-as-api`
+
+- **Check:** Content uses React children when consumers own the rendered
+  elements or need free-form composition.
+- **Prefer:** Use data props when the component must own, transform, order, or
+  constrain the rendered elements. Do not support equivalent children and data
+  APIs without a concrete need.
+- **Authority:** `contributor-docs/adrs/adr-004-children-as-api.md`
+
+## `component-review.file-structure`
+
+- **Check:** New components use a PascalCase directory and colocate
+  applicable implementation, styles, tests, stories, docs metadata, and exports
+  according to repository conventions.
+- **Prefer:** Name subcomponent files with the parent component prefix for
+  discoverability.
+- **Authority:** `contributor-docs/adrs/adr-013-file-structure.md`
+
+## `component-review.internal-modules`
+
+- **Check:** New shared modules that are not public API live under
+  `packages/react/src/internal` and are not exported from public entrypoints.
+- **Prefer:** Keep implementation details internal until a supported public API
+  is intentionally designed.
+- **Authority:** `contributor-docs/adrs/adr-015-internal-modules.md`
+
+## `component-review.stable-identifiers` (advisory)
+
+- **Check:** Newly added component roots, public subcomponents, and meaningful
+  structural parts follow the established `data-component` naming contract.
+- **Prefer:** Use PascalCase component API names, keep state in separate data
+  attributes, and test stable identifier values.
+- **Authority:** `contributor-docs/adrs/adr-023-stable-selectors-api.md`