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/javascript/settings.js

@@ -0,0 +1,95 @@
+/**
+ * javascript/settings.js
+ *
+ * Settings panel: reads/writes unraid-podman's own configuration via
+ * ajax/settings.php (podman.cfg + the autostart list) — not a
+ * PodmanClient/libpod concern, see that file's header comment.
+ */
+(function () {
+  'use strict';
+  const P = window.Podman;
+  let autostartNames = [];
+
+  function renderAutostart() {
+    const tbody = P.el('autostart-tbody');
+    tbody.innerHTML = autostartNames.length
+      ? autostartNames.map(function (name, i) {
+        return '<tr data-index="' + i + '">' +
+          '<td class="tnum">' + (i + 1) + '</td>' +
+          '<td>' + P.escapeHtml(name) + '</td>' +
+          '<td class="podman-actions">' +
+          '<button class="podman-btn podman-btn-icon" data-action="up"' + (i === 0 ? ' disabled' : '') + ' title="Move up">&#8593;</button>' +
+          '<button class="podman-btn podman-btn-icon" data-action="down"' + (i === autostartNames.length - 1 ? ' disabled' : '') + ' title="Move down">&#8595;</button>' +
+          '<button class="podman-btn podman-btn-icon" data-action="remove" title="Remove from autostart">&#128465;</button>' +
+          '</td></tr>';
+      }).join('')
+      : '<tr><td colspan="3" class="podman-empty-note">No containers in the autostart chain.</td></tr>';
+  }
+
+  function saveAutostart() {
+    return P.post('settings', 'autostart_save', { names: autostartNames }).catch(function (err) {
+      alert('Could not save autostart order: ' + err.message);
+    });
+  }
+
+  function fillForm(settings) {
+    P.el('settings-storage-path').value = settings.storagePath;
+    P.el('settings-storage-size').value = settings.storageImageSizeGb;
+    P.el('settings-enabled').checked = settings.enabled;
+    P.el('settings-stop-timeout').value = settings.stopTimeoutSeconds;
+
+    autostartNames = settings.autostart.slice();
+    renderAutostart();
+
+    const versions = settings.packageVersions || {};
+    const order = ['PODMAN', 'CONMON', 'CRUN', 'NETAVARK', 'AARDVARK_DNS', 'PASST', 'FUSE_OVERLAYFS'];
+    P.el('settings-package-versions').textContent = order
+      .map(function (k) { return k.toLowerCase().replace('_', '-') + ' ' + (versions[k + '_INSTALLED_VERSION'] || '?'); })
+      .join(' · ');
+  }
+
+  function load() {
+    return P.get('settings', 'get').then(fillForm).catch(function (err) {
+      alert('Could not load settings: ' + err.message);
+    });
+  }
+
+  function save() {
+    const body = {
+      storagePath: P.el('settings-storage-path').value.trim(),
+      storageImageSizeGb: parseInt(P.el('settings-storage-size').value, 10) || 20,
+      enabled: P.el('settings-enabled').checked,
+      stopTimeoutSeconds: parseInt(P.el('settings-stop-timeout').value, 10) || 10,
+    };
+    return P.post('settings', 'save', body).then(function () {
+      alert('Saved. Restart podman (rc.podman restart) to apply storage/enabled changes.');
+    }).catch(function (err) {
+      alert('Save failed: ' + err.message);
+    });
+  }
+
+  function init() {
+    P.el('settings-save-btn').addEventListener('click', save);
+
+    P.el('autostart-tbody').addEventListener('click', function (e) {
+      const btn = e.target.closest('button[data-action]');
+      if (!btn) return;
+      const i = parseInt(btn.closest('tr').dataset.index, 10);
+      const action = btn.dataset.action;
+
+      if (action === 'remove') {
+        autostartNames.splice(i, 1);
+      } else if (action === 'up' && i > 0) {
+        [autostartNames[i - 1], autostartNames[i]] = [autostartNames[i], autostartNames[i - 1]];
+      } else if (action === 'down' && i < autostartNames.length - 1) {
+        [autostartNames[i + 1], autostartNames[i]] = [autostartNames[i], autostartNames[i + 1]];
+      }
+      renderAutostart();
+      saveAutostart();
+    });
+
+    return load();
+  }
+
+  P.registerPanel('settings', { init: init, refresh: load });
+})();