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/containers.php

@@ -0,0 +1,132 @@
+<?php
+/**
+ * ajax/containers.php
+ *
+ * Backs the Containers panel (and the container rows nested inside the
+ * Pods panel — see ajax/pods.php). All actions go through PodmanClient,
+ * i.e. the real libpod REST API over podman.sock; nothing here shells out.
+ *
+ * Actions (?action=...):
+ *   list      GET  -> normalized array of containers for the table view
+ *   inspect   GET  (&id=...) -> raw inspect JSON, for a detail dialog
+ *   start     POST {"id": "..."}
+ *   stop      POST {"id": "...", "timeout": 10}
+ *   restart   POST {"id": "...", "timeout": 10}
+ *   remove    POST {"id": "...", "force": false}
+ *   logs      GET  (&id=...&tail=200) -> plain text
+ */
+
+declare(strict_types=1);
+
+require __DIR__ . '/../include/bootstrap.php';
+
+$action = $_GET['action'] ?? '';
+
+switch ($action) {
+    case 'list':
+        podman_json_response(containers_list($client));
+        break;
+
+    case 'inspect':
+        $id = (string) ($_GET['id'] ?? '');
+        if ($id === '') {
+            podman_json_error('Missing id', 400);
+        }
+        podman_json_response($client->inspectContainer($id));
+        break;
+
+    case 'logs':
+        $id = (string) ($_GET['id'] ?? '');
+        if ($id === '') {
+            podman_json_error('Missing id', 400);
+        }
+        $tail = (int) ($_GET['tail'] ?? 200);
+        podman_json_response(['text' => $client->containerLogs($id, $tail)]);
+        break;
+
+    case 'start':
+        $body = podman_read_json_body();
+        $client->startContainer(require_id($body));
+        podman_json_response(['status' => 'started']);
+        break;
+
+    case 'stop':
+        $body = podman_read_json_body();
+        $client->stopContainer(require_id($body), (int) ($body['timeout'] ?? $podmanConfig->stopTimeoutSeconds));
+        podman_json_response(['status' => 'stopped']);
+        break;
+
+    case 'restart':
+        $body = podman_read_json_body();
+        $client->restartContainer(require_id($body), (int) ($body['timeout'] ?? $podmanConfig->stopTimeoutSeconds));
+        podman_json_response(['status' => 'restarted']);
+        break;
+
+    case 'remove':
+        $body = podman_read_json_body();
+        $client->removeContainer(require_id($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_id(array $body): string
+{
+    $id = (string) ($body['id'] ?? '');
+    if ($id === '') {
+        podman_json_error('Missing id in request body', 400);
+    }
+    return $id;
+}
+
+/**
+ * Normalizes libpod's /containers/json entries into exactly what the
+ * Containers table (javascript/containers.js) renders — keeping this
+ * shaping logic server-side means the frontend never has to know libpod's
+ * raw field names/quirks (e.g. Names is an array, State vs Status, etc).
+ *
+ * @return array<int,array<string,mixed>>
+ */
+function containers_list(PodmanClient $client): array
+{
+    $raw = $client->listContainers(true);
+    $out = [];
+
+    foreach ($raw as $c) {
+        $names = $c['Names'] ?? [];
+        $name = is_array($names) && count($names) > 0 ? ltrim((string) $names[0], '/') : podman_short_id((string) ($c['Id'] ?? ''));
+
+        $ports = [];
+        foreach (($c['Ports'] ?? []) as $p) {
+            if (isset($p['host_port'], $p['container_port'])) {
+                $ports[] = "{$p['host_port']}:{$p['container_port']}/" . ($p['protocol'] ?? 'tcp');
+            } elseif (isset($p['container_port'])) {
+                $ports[] = "{$p['container_port']}/" . ($p['protocol'] ?? 'tcp');
+            }
+        }
+
+        $startedAt = podman_parse_time($c['StartedAt'] ?? null);
+        $state = strtolower((string) ($c['State'] ?? 'unknown'));
+
+        $out[] = [
+            'id' => (string) ($c['Id'] ?? ''),
+            'shortId' => podman_short_id((string) ($c['Id'] ?? '')),
+            'name' => $name,
+            'image' => (string) ($c['Image'] ?? ''),
+            'state' => $state,
+            'status' => (string) ($c['Status'] ?? ''),
+            'health' => $c['Health']['Status'] ?? null,
+            'ports' => $ports,
+            'pod' => $c['Pod'] ?? null,
+            'podName' => $c['PodName'] ?? null,
+            'uptimeSeconds' => ($state === 'running' && $startedAt !== null) ? (time() - $startedAt) : null,
+            'createdAt' => podman_parse_time($c['Created'] ?? null),
+        ];
+    }
+
+    usort($out, static fn($a, $b) => strcmp($a['name'], $b['name']));
+    return $out;
+}