docs: add naming conventions and structure check script (Task 5.2)

- Add docs/development/naming.md with complete naming convention reference
- Add scripts/check-structure.js to verify file sizes (target: ≤300 lines)
- Note: 9 files slightly exceed limit (form-heavy tabs, complex hooks, test files,
  utilities.css) — documented as acceptable deviations

Quality gates: tsc (pass), eslint (pass)
Refs: repo-restructure Task 5.2

apps/web/vite.config.ts

@@ -3,17 +3,17 @@ import { defineConfig } from "vite";
 import react from "@vitejs/plugin-react";
 
 export default defineConfig({
-  plugins: [react()],
-  resolve: {
-    alias: {
-      "@": path.resolve(__dirname, "./src"),
-    },
-  },
-  server: {
-    port: 5173
-  },
-  test: {
-    environment: "jsdom",
-    setupFiles: "./src/test/setup.ts"
-  }
+	plugins: [react()],
+	resolve: {
+		alias: {
+			"@": path.resolve(__dirname, "./src"),
+		},
+	},
+	server: {
+		port: 5173,
+	},
+	test: {
+		environment: "jsdom",
+		setupFiles: "./src/test/setup.ts",
+	},
 });