feat: add API optimizations, cache invalidation and comprehensive test suite

- Add abort controllers and request deduplication to composables
- Add entity type cache invalidation on create/update/delete flows
- Add 179 new tests (utilities, services, composables, components)
- Fix Vue runtime warnings in structure editors

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

package.json

@@ -30,6 +30,7 @@
     "@types/node": "^25.2.1",
     "@typescript-eslint/eslint-plugin": "^8.44.1",
     "@typescript-eslint/parser": "^8.44.1",
+    "@vitejs/plugin-vue": "^6.0.4",
     "@vue/test-utils": "^2.4.6",
     "eslint": "^9.36.0",
     "eslint-plugin-vue": "^10.5.0",