refactor(audit): type-safe enums, expanded coverage, and crash-safe logging

Replace magic strings with AuditAction/AuditStatus enums across all consumers,
add logAuditWithCurrentUser() convenience wrapper, extend audit coverage to
data import, result export, app update, and ERP credentials operations, and
harden crash handlers with try/catch to prevent audit failures from cascading.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

tests/fixtures/other-factories.test.ts

@@ -91,7 +91,7 @@ describe('AuditLogFactory', () => {
   it('creates audit log with default values', () => {
     const entry = AuditLogFactory.createAuditLog()
 
-    expect(entry.timestamp).toBeInstanceOf(Date)
+    expect(typeof entry.timestamp).toBe('string')
     expect(entry.action).toBe(AuditAction.LOGIN)
     expect(entry.status).toBe(AuditStatus.SUCCESS)
     expect(entry.userId).toBe('USR-001')