Add owner-only logging and Brickset API call tracking

LIM configured no logging at all, so the instruction fetcher had no trail to follow. Adds a rotating file handler on the root logger plus two owner-only admin pages.

- Admin > Logs: filter by level, source and text; tracebacks kept with their error; auto-refresh, raw download, rotated-file browsing and rotate-now

- Admin > Logs > Brickset API calls: every outbound call recorded with method, params, caller, duration, result count and error, plus daily quota accounting (only getSets counts) and a comparison against getKeyUsageStats

- New owner concept (services/ownership.py): a single account, distinct from is_admin, since these pages expose other admins activity. Defaults to the first admin; flask owner show/set to change

- Services now log through module loggers; retention setting and pruning for call records

- New CLI: flask owner show/set, flask logs path/prune

- New table brickset_api_calls, created automatically at boot; LOG_* env vars, /data/logs in Docker

app/templates/admin/instruction_fetch.html

@@ -15,6 +15,15 @@
         </p>
     </div>
     <div class="col-auto">
+        {% if current_user_is_owner %}
+        <a href="{{ url_for('logs.index', source='app.services.instruction_fetcher') }}"
+           class="btn btn-outline-dark">
+            <i class="bi bi-journal-text"></i> Fetcher log
+        </a>
+        <a href="{{ url_for('logs.brickset') }}" class="btn btn-outline-dark">
+            <i class="bi bi-cloud"></i> API calls
+        </a>
+        {% endif %}
         <a href="{{ url_for('admin.dashboard') }}" class="btn btn-outline-secondary">
             <i class="bi bi-arrow-left"></i> Back
         </a>