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/compose.js

@@ -0,0 +1,83 @@
+/**
+ * javascript/compose.js
+ *
+ * Compose panel: project list + read-only YAML view + up/down/pull,
+ * backed by ajax/compose.php. See that file's header comment — this is
+ * the one panel whose backend shells out to the `podman compose` CLI,
+ * because no REST equivalent for Compose exists in libpod.
+ */
+(function () {
+  'use strict';
+  const P = window.Podman;
+  let projects = [];
+  let selected = null;
+
+  function statusChip(status) {
+    const cls = status === 'up' ? 'podman-chip-good' : (status === 'down' ? 'podman-chip-neutral' : 'podman-chip-warn');
+    return '<span class="podman-chip ' + cls + '"><span class="d"></span>' + P.escapeHtml(status) + '</span>';
+  }
+
+  function renderSidebar() {
+    P.el('compose-sidebar').innerHTML = projects.map(function (p) {
+      return '<div class="podman-compose-proj' + (p.name === selected ? ' active' : '') + '" data-name="' + P.escapeHtml(p.name) + '">' +
+        '<div class="name" style="display:flex; justify-content:space-between; gap:8px;">' + P.escapeHtml(p.name) + ' ' + statusChip(p.status) + '</div>' +
+        '<div class="path">' + P.escapeHtml(p.path) + '</div>' +
+        '</div>';
+    }).join('') || '<div class="podman-empty-note">No compose projects under /boot/config/plugins/podman/compose/</div>';
+  }
+
+  function loadYaml(name) {
+    P.el('compose-title').textContent = name + ' / compose.yaml';
+    P.el('compose-yaml').textContent = 'Loading…';
+    return P.get('compose', 'get', { project: name }).then(function (data) {
+      P.el('compose-yaml').textContent = data.yaml;
+    }).catch(function (err) {
+      P.el('compose-yaml').textContent = 'Error: ' + err.message;
+    });
+  }
+
+  function selectProject(name) {
+    selected = name;
+    renderSidebar();
+    loadYaml(name);
+  }
+
+  function loadProjects() {
+    return P.get('compose', 'list').then(function (data) {
+      projects = data;
+      if (!selected && projects.length > 0) selected = projects[0].name;
+      renderSidebar();
+      if (selected) loadYaml(selected);
+    }).catch(function (err) {
+      P.el('compose-sidebar').innerHTML = '<div class="podman-error" style="padding:14px;">' + P.escapeHtml(err.message) + '</div>';
+    });
+  }
+
+  function runAction(action) {
+    if (!selected) return;
+    const btn = P.el('compose-action-' + action);
+    btn.disabled = true;
+    P.post('compose', action, { project: selected }).then(function (data) {
+      alert((data.output || 'Done.').slice(0, 2000));
+      return loadProjects();
+    }).catch(function (err) {
+      alert('podman compose ' + action + ' failed: ' + err.message);
+    }).finally(function () {
+      btn.disabled = false;
+    });
+  }
+
+  function init() {
+    P.el('compose-sidebar').addEventListener('click', function (e) {
+      const item = e.target.closest('.podman-compose-proj[data-name]');
+      if (item) selectProject(item.dataset.name);
+    });
+    P.el('compose-action-up').addEventListener('click', function () { runAction('up'); });
+    P.el('compose-action-down').addEventListener('click', function () { runAction('down'); });
+    P.el('compose-action-pull').addEventListener('click', function () { runAction('pull'); });
+
+    return loadProjects();
+  }
+
+  P.registerPanel('compose', { init: init, refresh: loadProjects });
+})();