Rework Dashboard, add toasts, container folders/icons/WebUI links, detail tabs

Dashboard:
- Plain-count stat tiles (Running/Stopped/Pods/Images/Volumes/Networks)
  separated from a single "Resource Usage" card (CPU/Memory/Swap/Storage
  meter rows) instead of forcing both into one tile grid, which produced
  awkward spanning-tile/dead-cell layouts.
- Fixed CPU usage never changing (libpod's own cpuUtilization is computed
  once and never resampled) by computing it from /proc/stat deltas instead.
- Fixed memory usage reading far too high by using /proc/meminfo's
  MemAvailable instead of libpod's raw (non-reclaimable-aware) memFree.
- Added an Autostart Queue table reusing podman-autostart.sh's own
  failure-counter files.
- Dashboard and Containers now auto-refresh every ~2s (paused when the
  tab is hidden or a modal is open).

Toasts:
- Real success/warn/error/info toast notifications replacing every
  alert() used for one-way feedback, across every panel.

Container detail modal:
- 5 new tabs: Resources, Logs, Console, Events, Healthcheck.

Containers panel:
- Folders to group containers (name + icon), stored in the plugin's own
  folders.json — a folder's header always shows an icon+name+status chip
  per member, matching Unraid's own Docker page folders. "Move to
  Folder" becomes "Remove from Folder" once a container is already
  grouped.
- Containers can carry an icon URL and a WebUI URL (small button next to
  the name), both stored as container labels and auto-filled from
  templates where applicable.
- Settings: an "Add container" control for the Autostart order table.

Fixes:
- Context menus now measure their own rendered size and flip above the
  anchor when there isn't room below, instead of running off-screen.
- Containers table now uses table-layout:fixed with explicit column
  widths — auto layout was shifting every column (and the header) on
  every folder expand/collapse, and briefly again when a flex wrapper
  was mistakenly placed directly on a <td>.

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

webui/plugins/podman/ajax/containers.php

@@ -18,6 +18,11 @@
  *   kill      POST {"id": "...", "signal": "SIGKILL"}
  *   rename    POST {"id": "...", "name": "..."}
  *   logs      GET  (&id=...&tail=200) -> plain text
+ *   events    GET  (&id=...&since=<unix seconds, default 7d ago>) -> array
+ *             of this one container's already-happened events (create,
+ *             start, stop, died, ...) — a bounded historical query, not a
+ *             live stream; see PodmanClient::containerEvents()'s own doc
+ *             comment for why that distinction matters here.
  *   list_gpus GET  -> detected AMD/Intel GPUs (/dev/dri), for the Create Container form's optional passthrough toggle
  *   check_updates GET -> {"<image ref>": {"updateAvailable": bool, "error": "..."?}} for every image currently in use
  *   create    POST {"image": "...", "name": "...", "networkMode": "bridge"|"host"|"none"|"<custom-network-name>",
@@ -26,7 +31,8 @@
  *                    "volumes": [{"kind": "named"|"path", "source": "myvol"|"/mnt/...", "containerPath": "/data"}],
  *                    "env": [{"key": "...", "value": "..."}], "restartPolicy": "no", "pod": "<existing-pod-name>",
  *                    "gpuDevices": ["/dev/dri/renderD128", "/dev/dri/card0"],
- *                    "privileged": false, "startAfterCreate": true}
+ *                    "privileged": false, "startAfterCreate": true, "icon": "https://..." (optional),
+ *                    "webuiUrl": "http://10.1.1.1:8080/" (optional)}
  */
 
 declare(strict_types=1);
@@ -57,6 +63,15 @@ switch ($action) {
         podman_json_response(['text' => $client->containerLogs($id, $tail)]);
         break;
 
+    case 'events':
+        $id = (string) ($_GET['id'] ?? '');
+        if ($id === '') {
+            podman_json_error('Missing id', 400);
+        }
+        $since = (int) ($_GET['since'] ?? (time() - 7 * 86400));
+        podman_json_response($client->containerEvents($id, $since));
+        break;
+
     case 'start':
         $body = podman_read_json_body();
         $client->startContainer(require_id($body));
@@ -278,6 +293,19 @@ function build_container_spec(string $image, array $body): array
         $spec['name'] = $name;
     }
 
+    $icon = trim((string) ($body['icon'] ?? ''));
+    $webuiUrl = trim((string) ($body['webuiUrl'] ?? ''));
+    $labels = [];
+    if ($icon !== '') {
+        $labels['podman-webui.icon'] = $icon;
+    }
+    if ($webuiUrl !== '') {
+        $labels['podman-webui.weburl'] = $webuiUrl;
+    }
+    if ($labels !== []) {
+        $spec['labels'] = $labels;
+    }
+
     $env = [];
     foreach (($body['env'] ?? []) as $row) {
         $key = trim((string) ($row['key'] ?? ''));
@@ -470,6 +498,14 @@ function containers_list(PodmanClient $client): array
             'cpuPercent' => $cpuPercent,
             'memUsageBytes' => $memUsageBytes,
             'memLimitBytes' => $memLimitBytes,
+            // Set at create time (see build_container_spec()) from either
+            // the template it was created from or a manually-entered URL —
+            // this plugin's own label, not Unraid's real Docker manager's
+            // net.unraid.docker.icon (this isn't Docker, so reusing that
+            // name would misleadingly imply real interop with tools that
+            // read it).
+            'icon' => $c['Labels']['podman-webui.icon'] ?? null,
+            'webUrl' => $c['Labels']['podman-webui.weburl'] ?? null,
         ];
     }