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/SignalTree.tsx

@@ -2,7 +2,7 @@ import { h, Fragment } from 'preact';
 import { useState, useEffect, useRef, useMemo } from 'preact/hooks';
 import type { SignalRef, StateVar } from './lib/types';
 import SyntheticWizard from './SyntheticWizard';
-import SyntheticEditor from './SyntheticEditor';
+import SyntheticGraphEditor from './SyntheticGraphEditor';
 import GroupsTree from './GroupsTree';
 import ChannelFinderModal from './ChannelFinderModal';
 
@@ -499,7 +499,7 @@ export default function SignalTree({ onDragStart, width, panelId, statevars, onS
       )}
 
       {editSynthetic && (
-        <SyntheticEditor
+        <SyntheticGraphEditor
           name={editSynthetic}
           onClose={() => setEditSynthetic(null)}
           onSaved={loadAllSignals}