feat: stack glob patterns and route severity levels (#1651)

* feat: add stack glob patterns and route severity levels

Operators can filter notification routes and mute rules with anchored * globs, and routes can target info, warning, or error. Matching is fail-closed for unsafe stored patterns; write paths keep partial-PUT semantics and ReDoS caps.

* test: split mute and routing chip tests to avoid dialog race

* fix: move stack pattern client validator out of PatternChips

* fix: bound stack glob matching and atomic pattern chip saves

backend/src/__tests__/notification-matchers.test.ts

@@ -73,6 +73,36 @@ describe('notificationMatchers', () => {
     })).toBe(true);
   });
 
+  it('matches stack globs with OR across patterns', () => {
+    expect(matchesNotificationFilters(baseCtx, {
+      node_id: null,
+      stack_patterns: ['prod-*', 'my-app'],
+      label_ids: null,
+      categories: null,
+    })).toBe(true);
+    expect(matchesNotificationFilters({ ...baseCtx, stackName: 'prod-web' }, {
+      node_id: null,
+      stack_patterns: ['prod-*'],
+      label_ids: null,
+      categories: null,
+    })).toBe(true);
+    expect(matchesNotificationFilters(baseCtx, {
+      node_id: null,
+      stack_patterns: ['prod-*'],
+      label_ids: null,
+      categories: null,
+    })).toBe(false);
+  });
+
+  it('fails closed on invalid stored stack patterns', () => {
+    expect(matchesNotificationFilters(baseCtx, {
+      node_id: null,
+      stack_patterns: ['****'],
+      label_ids: null,
+      categories: null,
+    })).toBe(false);
+  });
+
   it('detects when stack labels are needed', () => {
     expect(ruleNeedsStackLabels([{ node_id: null, stack_patterns: [], label_ids: [1], categories: null }])).toBe(true);
     expect(ruleNeedsStackLabels([{ node_id: null, stack_patterns: [], label_ids: null, categories: null }])).toBe(false);