Add Stop Podman to Settings, alongside Start/Restart

Rounds out the Podman Service card to the full start/stop/restart trio.
Stop and Restart both get a confirm() first — both actually stop every
running container (with its own configured grace period) before touching
the API service itself, not just the service process; worth surfacing
that explicitly rather than letting it be a surprise.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

webui/plugins/podman/Podman.page

@@ -238,15 +238,17 @@ function podman_asset_version(string $relPath): string
       <div class="podman-grid">
         <div class="podman-card">
           <div class="podman-card-head">
-            <div><h2>Podman Service</h2><div class="sub">Start, restart, or check the podman.sock backend — no terminal needed.</div></div>
+            <div><h2>Podman Service</h2><div class="sub">Start, stop, restart, or check the podman.sock backend — no terminal needed.</div></div>
           </div>
           <div class="podman-card-pad">
             <div class="podman-service-row">
               <span class="podman-chip podman-chip-neutral" id="settings-service-chip"><span class="d"></span>Checking…</span>
               <button class="podman-btn" id="settings-service-status-btn">Refresh Status</button>
               <button class="podman-btn podman-btn-primary" id="settings-service-start-btn">&#9654; Start Podman</button>
+              <button class="podman-btn podman-btn-ghost podman-btn-danger" id="settings-service-stop-btn">&#9632; Stop Podman</button>
               <button class="podman-btn" id="settings-service-restart-btn">&#8635; Restart Podman</button>
             </div>
+            <div class="hint">Stop/Restart first stop all running containers (each gets its own configured grace period) — not just the API service.</div>
             <div class="podman-log-pane" id="settings-service-log" style="display:none;"></div>
           </div>
         </div>