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/Canvas.tsx

@@ -18,6 +18,7 @@ import LinkWidget from './widgets/LinkWidget';
 import ContextMenu from './ContextMenu';
 import InfoPanel from './InfoPanel';
 import SplitLayout from './SplitLayout';
+import LogicDialogs from './LogicDialogs';
 
 const COMPONENTS: Record<string, any> = {
   textview:  TextView,
@@ -119,6 +120,8 @@ export default function Canvas({ iface, onNavigate, timeRange }: Props) {
         {infoSignal && (
           <InfoPanel signal={infoSignal} onClose={() => setInfoSignal(null)} />
         )}
+
+        <LogicDialogs />
       </div>
     );
   }
@@ -159,6 +162,8 @@ export default function Canvas({ iface, onNavigate, timeRange }: Props) {
       {infoSignal && (
         <InfoPanel signal={infoSignal} onClose={() => setInfoSignal(null)} />
       )}
+
+      <LogicDialogs />
     </div>
   );
 }