AI Implementation feature(898): Admin Area General Settings and Categories 1.16 (#38)

docs/architecture/key-files.md

@@ -3,7 +3,7 @@ type: architecture
 title: Key Files Index
 description: One-line responsibility for important source and contract-test files, including strict event-window validation and the public bootstrap SSE listener.
 tags: [architecture, key-files, event-window, validation, default-challenge-ip, sse, bootstrap, migrations]
-timestamp: 2026-07-22T18:37:00Z
+timestamp: 2026-07-22T19:18:00Z
 ---
 
 # Backend
@@ -25,7 +25,7 @@ timestamp: 2026-07-22T18:37:00Z
 | `backend/src/modules/admin/general.service.ts` | Reads/writes global settings, filters available theme files, and publishes the `general` SSE notification after updates. |
 | `backend/src/modules/auth/auth.controller.ts` | Registers authentication and account endpoints. |
 | `backend/src/modules/auth/auth.service.ts` | Handles sessions, authentication, registration, and password changes. |
-| `backend/src/modules/uploads/uploads.controller.ts` | Registers admin-only multipart uploads, including Sharp-backed site-logo format validation. |
+| `backend/src/modules/uploads/uploads.controller.ts` | Registers admin-only multipart uploads, including Sharp-backed site-logo format validation and strict category-icon decode (rejects undecodable / non-image buffers with HTTP 400 before any filesystem write so existing icons are preserved). |
 | `backend/src/modules/admin/dto/general.dto.ts` | Zod contract for `PUT /api/v1/admin/general/settings`; both event timestamps are required ISO-8601 values and end must be strictly after start. |
 | `tests/backend/admin-general-event-window.spec.ts` | Focused contract tests for valid, empty, malformed, equal, and reversed event-window timestamps. |
 | `tests/backend/admin-general-service.spec.ts` | General-settings schema and service tests, including per-field empty datetime failures and settings-event emission. |
@@ -52,7 +52,7 @@ timestamp: 2026-07-22T18:37:00Z
 | `frontend/src/app/features/shell/tabs/quick-tabs.component.ts` | Main shell navigation tabs. |
 | `frontend/src/app/features/shell/change-password/change-password-modal.component.ts` | Change-password form modal. |
 | `frontend/src/app/features/admin/general.component.ts` | `AdminGeneralComponent` reactive form for `/admin/general` — per-field inline error rendering (page-title + event-start + event-end), logo upload wiring, welcome Markdown preview, event-state derivation, and SSE `general` event handling. |
-| `frontend/src/app/features/admin/categories/category-form-modal.component.ts` | Standalone OnPush modal for create + edit; owns the `CategoryFormGroup`, exposes the pure `syncCategoryForm` helper, and reacts to `open` / `mode` / `category` signal inputs via a `markForCheck` effect so edit prefill reaches the DOM. |
+| `frontend/src/app/features/admin/categories/category-form-modal.component.ts` | Standalone OnPush modal for create + edit; owns the `CategoryFormGroup`, exposes the pure `syncCategoryForm` helper, binds `[formGroup]` on its template `<form>`, accepts `errorMessage` + `saving` parent inputs (renders `cf-error` and disables OK while saving), and reacts to `open` / `mode` / `category` signal inputs via a `markForCheck` effect so edit prefill reaches the DOM. |
 | `frontend/src/app/features/admin/general.pure.ts` | Pure General Settings helpers, including required datetime validation, field messages, UTC conversion, end-after-start validation, and the default-challenge-address IPv4/hostname validator/normalizer/message trio. |
 | `tests/frontend/admin-general-pure.spec.ts` | Pure client-contract tests for required event timestamps, datetime messaging, UTC conversion, event-window ordering, and default-challenge-address validation, error mapping, and normalization. |
 | `tests/frontend/admin-categories-form-modal.spec.ts` | Tests the pure `syncCategoryForm` helper that drives the edit/create prefill in `CategoryFormModalComponent`: system-row abbreviation lock, user-row unlock, re-population on second invocation, clearing on create, and iconPreview passthrough. |