# Architecture Hardening Backlog

**Date:** 2026-03-30
**Purpose:** Keep the remaining cleanup work for the current quality/security scope in a single prioritized list, so small hardening slices can be completed before larger redesign work.

## Recently Completed

- SSE audience model narrowed to canonical `user:*`, `permission:*`, and `resource:*` scopes only
- CI architecture guardrail added for SSE audience scoping
- import boundaries hardened for server dispo workbooks and browser spreadsheet uploads
- AI and SMTP runtime diagnostics sanitized before they reach logs or admin-facing error messages
- transitive audit hotspots for `flatted` and `picomatch` pinned through root `pnpm.overrides`
- `apps/web` export paths migrated from direct `xlsx` usage to a shared `exceljs` workbook export helper
- `packages/application` workbook reading and `packages/engine` XLSX export serialization migrated from `xlsx` to `exceljs`
- `pnpm audit --audit-level=high` no longer reports high-severity dependency findings
- `apps/web` now has focused Vitest coverage for browser spreadsheet parsing and skill-matrix workbook parsing
- cron routes, Redis helpers, reminder scheduling, webhook dispatching, and SSE fallback paths now use structured logger calls instead of raw `console.*`
- `packages/api` now has focused Vitest coverage for reminder scheduler and webhook dispatcher logging failures
- `apps/web` typecheck is now decoupled from generated `.next-e2e` artifacts via a dedicated `tsconfig.typecheck.json`
- comment entity support is now centralized across shared constants, API registry policy, assistant tool metadata, and the web comment target API without pretending a second consumer exists
- `resource` is now onboarded as the second real comment entity, reusing the same ownership and staff-visibility rules as the resource detail route
- comment mention autocomplete now uses a dedicated entity-scoped API route instead of inheriting the narrower `user.listAssignable` audience
- runtime secret handling is now environment-first end to end: admin updates no longer persist new operational secrets, runtime status is surfaced explicitly, and legacy database secret copies can be cleared through a dedicated cleanup path
- `apps/web` system settings UI is now decomposed into section components with shared secret/runtime helpers, bringing all files in that slice back under the file-size guardrail
- the first API-side `assistant-tools` extraction is in place: settings, system-role config, webhooks, audit log access, and shoring ratio now live in a dedicated domain module with shared assistant-tool types
- the advanced timeline assistant toolset now lives in its own domain module, keeping the high-risk read/mutation pairings out of the monolithic router without changing the assistant contract
- the adjacent allocation planning assistant helpers now live in their own domain module, covering allocation listing, budget status, and the core allocation create/cancel/status mutations without changing the assistant contract
- the neighboring vacation and holiday assistant helpers now live in their own domain module, covering vacation-balance reads, regional/resource holiday inspection, and holiday calendar admin mutations without changing the assistant contract
- the adjacent roles, skill-search, and lightweight analytics assistant helpers now live in their own domain module, covering role CRUD plus `search_by_skill`, `get_statistics`, and `get_chargeability` without changing the assistant contract
- the neighboring client and org-unit admin mutations now live in their own domain module, keeping more CRUD wiring out of the monolithic router without changing the assistant contract
- the adjacent chargeability/computation read helpers now live in their own domain module, keeping the advanced financial transparency read models out of the monolithic router without changing the assistant contract
- the neighboring country and metro-city admin mutations now live in their own domain module, keeping more settings-side CRUD wiring out of the monolithic router without changing the assistant contract
- the adjacent management-level, utilization, calculation-rule, effort-rule, and experience-multiplier read helpers now live in their own domain module, further shrinking the monolithic assistant router without changing the assistant contract

## Next Up

Pin the next structural cleanup on the API side:
continue splitting `packages/api/src/router/assistant-tools.ts` into domain-oriented tool modules without changing the public tool contract.
The next clean slice should stay adjacent to the extracted domains and target one cohesive block such as the authenticated user/self-service assistant tools, or the remaining estimate and project admin helper clusters that are still embedded in the monolithic router.

## Remaining Major Themes

The small hardening slices are effectively exhausted.
The remaining work is now structural rather than another quick batch:

1. secrets and runtime configuration policy
2. oversized router decomposition
3. production-grade rate limiting
4. canonical image-based production delivery
5. performance hotspot reduction

## Working Rule

For the next batches, prefer work in this order:

1. remove or isolate known-risk runtime dependencies
2. add guardrails and tests around already-hardened code
3. only then expand architecture surface area
