docs: update root .md files to reflect current frontend state and planned UX enhancements

- ARCHITECTURE.md: fix diagram (Server Detail was "planned", now complete), expand
  frontend directory listing with all 5 pages, all server components, all hooks
- FRONTEND.md: note planned terrain/display_name/workshop_id fields on Mission/Mod
  types; add planned hooks table for Phases 1-5 of UX enhancement plan
- MODULES.md: annotate PlayerRepository with get_by_slot() and ThreadRegistry with
  get_rcon_client() as planned additions in Phase 4
- API.md: add "Upcoming Endpoints" section documenting all planned routes for
  Phases 1-5 of the UX enhancement plan
- README.md: update unit test count (69 → ~120), update frontend structure comment
  to list all current pages/components/hooks

API.md

@@ -1485,4 +1485,37 @@ Implemented via `slowapi` middleware.
 | `FILE_TOO_LARGE`            | 413         | Upload exceeds 500 MB                                 |
 | `NO_FILENAME`               | 400         | No filename in upload request                         |
 | `VALIDATION_ERROR`          | 400         | General validation failure                            |
-| `INTERNAL_ERROR`            | 500         | Unexpected server error                               |
+| `INTERNAL_ERROR`            | 500         | Unexpected server error                               |
+
+---
+
+## Upcoming Endpoints (UX Enhancement Plan)
+
+These endpoints are planned and will be added during the Arma 3 UX Enhancement implementation. They do not exist yet.
+
+### Phase 1 — Config UI Schema
+
+| Method | Path | Auth | Description |
+|--------|------|------|-------------|
+| GET | `/servers/{server_id}/config/ui-schema` | Bearer | Returns widget hints per field (`widget`, `label`, `placeholder`) for the frontend config editor |
+
+### Phase 2 — Mission Rotation
+
+| Method | Path | Auth | Description |
+|--------|------|------|-------------|
+| GET | `/servers/{server_id}/missions/rotation` | Bearer | Get current mission rotation list |
+| PUT | `/servers/{server_id}/missions/rotation` | Admin | Replace mission rotation (requires `config_version` for optimistic locking) |
+
+### Phase 4 — Player Kick / Ban
+
+| Method | Path | Auth | Description |
+|--------|------|------|-------------|
+| POST | `/servers/{server_id}/players/{slot_id}/kick` | Admin | Kick player by slot ID via RCon; requires `reason` in body |
+| POST | `/servers/{server_id}/players/{slot_id}/ban` | Admin | Ban player by slot ID via RCon + DB; requires `reason` and optional `duration_minutes` (`null` = permanent) |
+
+### Phase 5 — Log File Browser
+
+| Method | Path | Auth | Description |
+|--------|------|------|-------------|
+| GET | `/servers/{server_id}/logfiles` | Bearer | List historical `.rpt` log files with `filename`, `size_bytes`, `modified_at` |
+| GET | `/servers/{server_id}/logfiles/{filename}` | Bearer | Stream or return contents of a historical log file |