Add reproducible build system, native Unraid plugin, and WebUI

- versions.env pins podman, conmon, crun, netavark, aardvark-dns, passt,
  and fuse-overlayfs to verified upstream source checksums; SlackBuild
  recipes, scripts/build-packages.sh, checksums.sh, release.sh, and
  update-versions.sh implement the reproducible pipeline; GitHub Actions
  workflows build in a Slackware container and publish releases without
  committing any binaries.

- plugin/podman.plg installs/updates/removes all eight packages (the
  seven components plus the plugin's own unraid-podman scaffolding
  package) via upgradepkg, using the official Unraid array-event hook
  mechanism (event/disks_mounted, event/stopping) instead of editing
  /boot/config/go. rc.podman and the sbin/ helper scripts implement
  storage creation, config seeding/sync, preflight checks, autostart
  with per-container Safe-Mode, and package verify/update/rollback.

- webui/plugins/podman implements the Dashboard, Containers, Pods,
  Images, Volumes, Networks, Logs, Terminal, Compose, and Settings
  panels against the approved mockup (webui/mockups/prototype.html),
  talking to podman system service exclusively via PodmanClient.php
  (libpod REST API over the Unix socket), with two documented
  exceptions: Terminal's one-shot exec model and Compose's use of the
  podman compose CLI, since libpod has no REST equivalent for either.

- docs/ARCHITECTURE.md and docs/ROADMAP.md record the design decisions
  and honest current status (syntax-checked, unit- and
  integration-tested against fake sockets/servers; not yet run against
  a real Unraid/Podman/Slackware system).

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

webui/plugins/podman/ajax/pods.php

@@ -0,0 +1,103 @@
+<?php
+/**
+ * ajax/pods.php
+ *
+ * Backs the Pods panel. A pod is rendered as its own card with the member
+ * containers nested inside (see javascript/pods.js) — listPods() gives us
+ * the membership, and we cross-reference the container list for per-member
+ * status/image/ports rather than issuing one inspect call per container.
+ *
+ * Actions (?action=...):
+ *   list     GET  -> pods with nested container summaries
+ *   start    POST {"name": "..."}
+ *   stop     POST {"name": "...", "timeout": 10}
+ *   remove   POST {"name": "...", "force": false}
+ */
+
+declare(strict_types=1);
+
+require __DIR__ . '/../include/bootstrap.php';
+
+$action = $_GET['action'] ?? '';
+
+switch ($action) {
+    case 'list':
+        podman_json_response(pods_list($client));
+        break;
+
+    case 'start':
+        $body = podman_read_json_body();
+        $client->startPod(require_name($body));
+        podman_json_response(['status' => 'started']);
+        break;
+
+    case 'stop':
+        $body = podman_read_json_body();
+        $client->stopPod(require_name($body), (int) ($body['timeout'] ?? $podmanConfig->stopTimeoutSeconds));
+        podman_json_response(['status' => 'stopped']);
+        break;
+
+    case 'remove':
+        $body = podman_read_json_body();
+        $client->removePod(require_name($body), (bool) ($body['force'] ?? false));
+        podman_json_response(['status' => 'removed']);
+        break;
+
+    default:
+        podman_json_error("Unknown action '{$action}'", 400);
+}
+
+/** @param array<string,mixed> $body */
+function require_name(array $body): string
+{
+    $name = (string) ($body['name'] ?? '');
+    if ($name === '') {
+        podman_json_error('Missing name in request body', 400);
+    }
+    return $name;
+}
+
+/** @return array<int,array<string,mixed>> */
+function pods_list(PodmanClient $client): array
+{
+    $pods = $client->listPods();
+    $containersByPod = [];
+    foreach (containers_grouped_by_pod($client) as $podId => $members) {
+        $containersByPod[$podId] = $members;
+    }
+
+    $out = [];
+    foreach ($pods as $p) {
+        $id = (string) ($p['Id'] ?? '');
+        $out[] = [
+            'id' => $id,
+            'name' => (string) ($p['Name'] ?? ''),
+            'status' => strtolower((string) ($p['Status'] ?? 'unknown')),
+            'containersTotal' => (int) ($p['NumContainers'] ?? count($containersByPod[$id] ?? [])),
+            'infraId' => $p['InfraId'] ?? null,
+            'members' => $containersByPod[$id] ?? [],
+        ];
+    }
+    return $out;
+}
+
+/** @return array<string,array<int,array<string,mixed>>> keyed by pod id */
+function containers_grouped_by_pod(PodmanClient $client): array
+{
+    $grouped = [];
+    foreach ($client->listContainers(true) as $c) {
+        $podId = $c['Pod'] ?? null;
+        if (!is_string($podId) || $podId === '') {
+            continue;
+        }
+        $names = $c['Names'] ?? [];
+        $name = is_array($names) && count($names) > 0 ? ltrim((string) $names[0], '/') : podman_short_id((string) ($c['Id'] ?? ''));
+        $grouped[$podId][] = [
+            'id' => (string) ($c['Id'] ?? ''),
+            'name' => $name,
+            'image' => (string) ($c['Image'] ?? ''),
+            'state' => strtolower((string) ($c['State'] ?? 'unknown')),
+        ];
+    }
+    return $grouped;
+}