Fix architecture and README accuracy findings from review

- Topology: show the port mapping host 8090 -> container 8080, and note
  that searxng is internal to the compose network with no published port.
- Backend: logging is log/slog JSON.
- Scheduler: only the household-configurable times live in
  household_settings; week_rollover and the ai_runs purge are fixed.
- README: state the Node.js floor required by the committed lockfile.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

docs/ARCHITECTURE.md

@@ -20,8 +20,9 @@ Traefik v3.6 — 10.60.1.33
    │
    ▼
 docker compose project "mealquest" — 10.60.1.14
-   ├── mealquest   Go service + embedded PWA, port 8090
-   ├── searxng     sidecar for recipe search
+   ├── mealquest   Go service + embedded PWA, host 8090 → container 8080
+   ├── searxng     sidecar for recipe search; internal compose network
+   │               only, no published port
    └── Litestream  SQLite replication → Synology NAS 10.60.1.50
 ```
 
@@ -53,7 +54,7 @@ database is replicated by Litestream to the NAS.
 ## Backend stack and conventions
 
 - Go 1.25, `CGO_ENABLED=0`, a single static binary.
-- Router: `go-chi/chi/v5`. Logging: `log/slog` (structured).
+- Router: `go-chi/chi/v5`. Logging: `log/slog` JSON.
 - SQLite via `modernc.org/sqlite`, with `journal_mode=WAL`,
   `foreign_keys=ON` and `busy_timeout`. **One writer connection plus a read
   pool.** Queries generated by `sqlc`.
@@ -153,8 +154,12 @@ automatic** (D-021).
 
 ## Scheduler
 
-Times are in the household timezone; the defaults below are set in
-`household_settings`.
+Times are in the household timezone. The times of `day_of_reminder`
+(`reminder_time`) and `rotation_check` (`review_time`), and the day and time
+of `suggestions_weekly`, `plan_draft` and `shopping_chat_autosend`, are
+household settings in `household_settings` (`dinner_time` is also stored
+there); the table shows their defaults. `week_rollover` and the `ai_runs`
+purge are fixed and not configurable.
 
 | Schedule | When | Does |
 | --- | --- | --- |
@@ -163,8 +168,8 @@ Times are in the household timezone; the defaults below are set in
 | `shopping_chat_autosend` | Saturday 08:00 | Sends the Supply run to Google Chat. |
 | `day_of_reminder` | Daily 16:30 | Tonight's dinner reminder. |
 | `rotation_check` | Daily 09:00 | Asks "Keep it in rotation?" for tried dinners. |
-| `week_rollover` | Monday 00:05 | Freezes last week's Supply run into the Supply archive. |
-| `ai_runs` purge | Daily | Deletes `ai_runs` rows past 30-day retention. |
+| `week_rollover` | Monday 00:05 (fixed) | Freezes last week's Supply run into the Supply archive. |
+| `ai_runs` purge | Daily (fixed) | Deletes `ai_runs` rows past 30-day retention. |
 
 Runs are recorded in `schedule_runs` and executed through `jobs`.