frontend: optimize Claude context files and add legacy import linter warnings

frontend/.claude/rules/test-unit-vs-integration.md

@@ -0,0 +1,13 @@
+---
+paths:
+  - "src/**/*.test.{ts,tsx}"
+---
+
+# Unit vs Integration Tests
+
+| Extension | Environment | Use For |
+|-----------|-------------|---------|
+| `.test.ts` | Node (no DOM) | Pure logic, utils, transforms |
+| `.test.tsx` | JSDOM (browser) | Components, hooks, DOM interaction |
+
+Wrong extension = test silently passes or fails in CI. See [full rule](../skills/testing/rules/test-unit-vs-integration.md) for details.

frontend/.claude/skills/api-patterns/SKILL.md

@@ -33,36 +33,6 @@ Make API calls with Connect Query and handle responses properly.
 
 Regenerate protos: `task proto:generate` (from repo root)
 
-## Basic Patterns
-
-### Query
-
-```typescript
-import { useQuery } from '@connectrpc/connect-query';
-import { getUser } from 'protogen/user-UserService_connectquery';
-
-const { data, isLoading, error } = useQuery(
-  getUser,
-  { id: userId },
-  { enabled: !!userId }
-);
-```
-
-### Mutation
-
-```typescript
-import { useMutation } from '@connectrpc/connect-query';
-import { createUser } from 'protogen/user-UserService_connectquery';
-
-const mutation = useMutation(createUser, {
-  onSuccess: () => {
-    queryClient.invalidateQueries({ queryKey: ['getUser'] });
-  },
-});
-
-mutation.mutate({ name, config });
-```
-
 ## Rules
 
-See `rules/` directory for detailed guidance.
+See `rules/` directory for detailed guidance on queries, mutations, cache invalidation, and error handling.

frontend/.claude/skills/api-patterns/rules/use-connect-query.md

@@ -79,3 +79,4 @@ function ClusterList({ organizationId }: Props) {
 
 - [Connect Query Docs](https://connectrpc.com/docs/web/query/getting-started)
 - [TanStack Query Options](https://tanstack.com/query/latest/docs/framework/react/reference/useQuery)
+- See also: [use-react-query-for-server](../../state-management/rules/use-react-query-for-server.md) — when to use React Query vs Zustand

frontend/.claude/skills/code-standards/SKILL.md

@@ -18,12 +18,12 @@ Write code that is accessible, performant, type-safe, and maintainable.
 
 | Action | Rule |
 |--------|------|
-| Avoid any | `ts-no-any.md` |
-| Handle unknowns | `ts-use-unknown.md` |
 | Write components | `react-functional-only.md` |
 | Async code | `async-await-promises.md` |
 | Avoid legacy libs | `no-legacy.md` |
 
+`any` types and top-level regex are enforced by Biome (`noExplicitAny`, `useTopLevelRegex`).
+
 ## Commands
 
 ```bash

frontend/.claude/skills/code-standards/rules/no-legacy.md

@@ -101,3 +101,7 @@ When converting observables to React state, automatic behaviors must become expl
 
 - MobX stores: `src/state/` (do not add new files)
 - Chakra components: throughout codebase (migrate on touch)
+
+## See Also
+
+- [use-ui-registry](../../ui-development/rules/use-ui-registry.md) — Registry component usage and installation