fix(panel): P3 optional items — urlquery, aria-live, confirm-without-JS note

- Deliveries fragment/pagination links urlquery-encode the domain/app
  filters instead of splicing them into the query string raw.
- The four polled regions (deliveries rows, status, mail queue, system
  log) carry aria-live="polite" so a screen reader announces refreshes.
- security.md accepted risks note that data-confirm prompts are
  JavaScript-only and why that is acceptable.

docs/plans/code-review.md P3 fully checked off; CHANGELOG updated.

Co-authored-by: Cursor <cursoragent@cursor.com>

internal/web/view/templates/status_body.html

@@ -1,5 +1,5 @@
 {{define "status_body"}}
-<div id="status-body" data-poll hx-get="/status/fragment" hx-trigger="load" hx-swap="outerHTML">
+<div id="status-body" data-poll aria-live="polite" hx-get="/status/fragment" hx-trigger="load" hx-swap="outerHTML">
   <div class="card" id="overall">
     <h2>Overall <span class="st st-{{.OverallStatus}}">{{.OverallStatus}}</span></h2>
     <p class="muted">{{.OverallHeading}}</p>