perf: 프런트엔드 import 경계를 세분화

Gateway 화면을 route 단위로 지연 로딩하고 common runtime import를 실제 소유 leaf export로 분리한다.\n\npackage boundary와 route loading 회귀 테스트로 root barrel 재유입을 차단한다.

tools/check-package-boundaries.test.mjs

@@ -11,6 +11,10 @@ test('extracts multiline and type-only package imports', () => {
         extractImports("import {\n  GamePrisma,\n  type DatabaseClient\n} from '@sammo-ts/infra';")[0]?.specifier,
         '@sammo-ts/infra'
     );
+    assert.equal(
+        extractImports("import { type AppRouter, type Profile } from '@sammo-ts/gateway-api';")[0]?.typeOnly,
+        true
+    );
 });
 
 test('rejects infrastructure access and process diagnostics in logic', () => {
@@ -51,3 +55,35 @@ test('rejects prefixed and bare Node builtins in frontend source', () => {
         'app/game-frontend/src/example.ts: frontend production code may not import node:fs',
     ]);
 });
+
+test('requires frontend common and logic runtime imports to use leaf subpaths', () => {
+    const zone = {
+        name: 'game-frontend',
+        allowed: ['@sammo-ts/common', '@sammo-ts/logic'],
+        frontend: true,
+    };
+    const violations = checkSource({
+        source: [
+            "import { formatServerDateTime } from '@sammo-ts/common';",
+            "import { MESSAGE_MAILBOX_PUBLIC } from '@sammo-ts/logic';",
+            "import type { MessageType } from '@sammo-ts/logic';",
+        ].join('\n'),
+        relativePath: 'app/game-frontend/src/example.ts',
+        zone,
+    });
+
+    assert.deepEqual(violations, [
+        'app/game-frontend/src/example.ts: frontend runtime must import a leaf subpath from @sammo-ts/common',
+        'app/game-frontend/src/example.ts: frontend runtime must import a leaf subpath from @sammo-ts/logic',
+    ]);
+});
+
+test('allows the isolated battle simulator worker to load the logic runtime root', () => {
+    const violations = checkSource({
+        source: "const loadProcessor = () => import('@sammo-ts/logic');",
+        relativePath: 'app/game-frontend/src/workers/battleSimulator.worker.ts',
+        zone: { name: 'game-frontend', allowed: ['@sammo-ts/logic'], frontend: true },
+    });
+
+    assert.deepEqual(violations, []);
+});