Improve local rules persistence and dirty-state handling

test/web/rule-editor-contract.test.js

@@ -0,0 +1,16 @@
+import assert from 'node:assert/strict';
+import fs from 'node:fs';
+import path from 'node:path';
+import test from 'node:test';
+
+const root = path.resolve(import.meta.dirname, '../..');
+const component = fs.readFileSync(path.join(root, 'src/web/components/ClientOverviewPage.jsx'), 'utf8');
+const styles = fs.readFileSync(path.join(root, 'src/web/styles.css'), 'utf8');
+
+test('rule editor add latency stays constant and dirty exits are guarded', () => {
+  const rowRule = /\.client-local-rule \{([\s\S]*?)\n\}/.exec(styles)?.[1] || '';
+  assert.doesNotMatch(rowRule, /--rule-index|calc\(/);
+  assert.match(component, /addEventListener\('beforeunload', warnBeforeUnload\)/);
+  assert.match(component, /requestCloseLocalRules\(\)/);
+  assert.match(component, /localRulesPendingRestart/);
+});