Add control logic engine, panel logic dialogs, logic-edit restriction

Introduce server-side control-logic flow graphs (cron/alarm triggers,
Lua blocks) with CRUD endpoints, panel-logic lifecycle triggers and
user-interaction dialog nodes, and a synthetic node-graph editor.

Add an optional logic-editor allowlist (server.logic_editors) gating who
may add/edit panel logic and control logic, surfaced via /api/v1/me and
enforced in the API; hide logic affordances in the UI accordingly.

Update README, example config, and functional/technical specs to cover
all current features (plot panels, panel/control logic, local variables,
access control) and refresh the in-app manual and contextual help.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

web/src/EditMode.tsx

@@ -88,7 +88,8 @@ const STATIC_WIDGET_TYPES = [
 
 export default function EditMode({ initial, onDone }: Props) {
   const [iface, setIface] = useState<Interface>(initial ?? blankInterface());
-  const writable = canWrite(useAuth().level);
+  const me = useAuth();
+  const writable = canWrite(me.level);
   const [selectedIds, setSelectedIds] = useState<string[]>([]);
   const [dirty, setDirty] = useState(false);
   const [saving, setSaving] = useState(false);
@@ -670,12 +671,14 @@ export default function EditMode({ initial, onDone }: Props) {
               class={`center-tab${centerTab === 'layout' ? ' center-tab-active' : ''}`}
               onClick={() => setCenterTab('layout')}
             >Layout</button>
-            <button
-              class={`center-tab${centerTab === 'logic' ? ' center-tab-active' : ''}`}
-              onClick={() => setCenterTab('logic')}
-            >Logic{iface.logic && iface.logic.nodes.length > 0 ? ` (${iface.logic.nodes.length})` : ''}</button>
+            {me.canEditLogic && (
+              <button
+                class={`center-tab${centerTab === 'logic' ? ' center-tab-active' : ''}`}
+                onClick={() => setCenterTab('logic')}
+              >Logic{iface.logic && iface.logic.nodes.length > 0 ? ` (${iface.logic.nodes.length})` : ''}</button>
+            )}
           </div>
-          {centerTab === 'logic' ? (
+          {centerTab === 'logic' && me.canEditLogic ? (
             <LogicEditor
               graph={iface.logic ?? { nodes: [], wires: [] }}
               onChange={handleLogicChange}