feat(eslint-config): add boundaries plugin enforcing app→feature→core graph

- Install eslint-plugin-boundaries@^4.2.2 to enforce three-tag boundary model
- Configure element types: app, core-composition (core-api/core-cms), core, feature, tooling
- Enforce unidirectional dependency graph: apps→features→core, core-composition→features
- Add eslint.config.js to all 17 packages and apps (required for ESLint 9 flat config)
- Fix pre-existing linting issues to achieve clean lint pass

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

packages/core-ui/src/atoms/input/input.tsx

@@ -1,7 +1,7 @@
 import { forwardRef, type InputHTMLAttributes } from "react";
 import { cn } from "../../lib/utils";
 
-export interface InputProps extends InputHTMLAttributes<HTMLInputElement> {}
+export type InputProps = InputHTMLAttributes<HTMLInputElement>;
 
 export const Input = forwardRef<HTMLInputElement, InputProps>(
   ({ className, type, ...props }, ref) => {

packages/core-ui/src/atoms/label/label.tsx

@@ -1,7 +1,7 @@
 import { forwardRef, type LabelHTMLAttributes } from "react";
 import { cn } from "../../lib/utils";
 
-export interface LabelProps extends LabelHTMLAttributes<HTMLLabelElement> {}
+export type LabelProps = LabelHTMLAttributes<HTMLLabelElement>;
 
 export const Label = forwardRef<HTMLLabelElement, LabelProps>(
   ({ className, ...props }, ref) => {