# AEG-X-002 — Route Code-Splitting Refactoring

- **WBS / Requirement:** AEG-X-002 / REQ-PLAT-TOOL
- **Classification:** behavior-preserving frontend build refactoring
- **Selected on:** 2026-08-08

## Source / Assumption / Unknown / Decision Required

- **Source:** `frontend/src/app/router.ts` and the co-located tracked `router.js` initially statically import every route component; the actual 2026-08-08 production build reports a 501.14 kB gzip initial JavaScript chunk. A first TypeScript-only refactoring did not change build output, demonstrating that the Vite resolver uses the co-located JavaScript router entry in this repository.
- **Assumption:** Vue Router's supported lazy route-component function preserves every route path, metadata, guard behavior, and component API while moving feature code out of the initial chunk.
- **Unknown:** an approved application performance budget is not present. Chunk reduction is an observation, not a performance-gate pass.
- **Decision Required:** none for this refactoring. Budget approval, visual evidence, and large-list interaction evidence remain separate work.

## Change

- Replace route component static imports with lazy `import()` factories in both active co-located router entries.
- Load only the selected, validated UI provider at bootstrap instead of statically bundling both provider implementations and their vendor dependencies.

## Acceptance Evidence

- All existing route paths and metadata remain unchanged.
- `pnpm test` passed: 26 files / 58 tests. Preserved output: `evidence/AEG-X-002/frontend-regression-route-split_20260808.log`.
- `pnpm build` passed. Preserved output: `evidence/AEG-X-002/frontend-build-route-split_20260808.log`.
- The initial gzip JavaScript chunk changed from 501.14 kB to 423.76 kB and page chunks are emitted separately. Vite still warns because its default raw-size threshold is exceeded; the threshold was not changed and this is not an approved performance-gate pass.
- The selected-provider bootstrap refactoring is covered by `frontend/src/shared/ui/provider/tests/resolveUiProvider.spec.ts`: the native provider resolves and an unsupported provider rejects before mount. The final full regression result is 27 files / 60 tests, preserved in `evidence/AEG-X-002/frontend-regression-provider-lazy_20260808.log`.
- Final provider-lazy build evidence is `evidence/AEG-X-002/frontend-build-provider-lazy_20260808.log`. The app bootstrap chunk is 20.51 kB (7.35 kB gzip); the selected PrimeVue/AG Grid provider is a separate 1,515.61 kB (393.82 kB gzip) lazy chunk.

No API, provider, policy, database, capability, or route authorization behavior changes.
