fix: Contract, TaxProfile, TaxFilingSchedule에 대해 선제적으로 GetAllAsync API 및 구현체 추가

TaxBaik.Infrastructure/Repositories/TaxFilingScheduleRepository.cs

@@ -16,6 +16,14 @@ public class TaxFilingScheduleRepository(IDbConnectionFactory connectionFactory)
             schedule);
     }
 
+    public async Task<IEnumerable<TaxFilingSchedule>> GetAllAsync(CancellationToken cancellationToken = default)
+    {
+        using var conn = Conn();
+        return await conn.QueryAsync<TaxFilingSchedule>(
+            @"SELECT id, client_id, filing_type, due_date, filing_year, status, assigned_to, completed_date, notes, created_at, updated_at
+              FROM tax_filing_schedules ORDER BY due_date DESC");
+    }
+
     public async Task<TaxFilingSchedule?> GetByIdAsync(int id, CancellationToken cancellationToken = default)
     {
         using var conn = Conn();