feat(reports): parseOperationalFilters pure parser (Area scope)

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

tests/unit/services/reports/operational-filters.test.ts

@@ -0,0 +1,29 @@
+import { describe, expect, it } from 'vitest';
+
+import { parseOperationalFilters } from '@/lib/services/reports/operational-filters';
+
+function params(qs: string): URLSearchParams {
+  return new URLSearchParams(qs);
+}
+
+describe('parseOperationalFilters', () => {
+  it('returns undefined when no area param is present', () => {
+    expect(parseOperationalFilters(params(''))).toBeUndefined();
+    expect(parseOperationalFilters(params('from=x&to=y'))).toBeUndefined();
+  });
+
+  it('parses a single area', () => {
+    expect(parseOperationalFilters(params('area=A'))).toEqual({ areas: ['A'] });
+  });
+
+  it('parses a CSV of areas and trims whitespace', () => {
+    expect(parseOperationalFilters(params('area=A,%20B%20,C'))).toEqual({
+      areas: ['A', 'B', 'C'],
+    });
+  });
+
+  it('drops empty / whitespace-only entries, returning undefined when nothing is left', () => {
+    expect(parseOperationalFilters(params('area=%20,%20'))).toBeUndefined();
+    expect(parseOperationalFilters(params('area='))).toBeUndefined();
+  });
+});