test: fix date dependencies in cycle generator tests

- Add create_member_with_cycles helper that uses fixed 'today' date
- Update tests to use explicit 'today:' option instead of Date.utc_today()
- Prevents test failures when current date changes (e.g., in 2026+)
- Tests now explicitly delete and regenerate cycles with fixed dates
- Ensures consistent test behavior regardless of execution date

test/membership_fees/member_cycle_integration_test.exs

@@ -211,13 +211,18 @@ defmodule Mv.MembershipFees.MemberCycleIntegrationTest do
       initial_cycles = get_member_cycles(member.id)
       initial_count = length(initial_cycles)
 
-      # Manually trigger generation again
-      {:ok, _} = Mv.MembershipFees.CycleGenerator.generate_cycles_for_member(member.id)
+      # Use a fixed "today" date to avoid date dependency
+      # Use a date far enough in the future to ensure all cycles are generated
+      today = ~D[2025-12-31]
+
+      # Manually trigger generation again with fixed "today" date
+      {:ok, _} =
+        Mv.MembershipFees.CycleGenerator.generate_cycles_for_member(member.id, today: today)
 
       final_cycles = get_member_cycles(member.id)
       final_count = length(final_cycles)
 
-      # Should have same number of cycles
+      # Should have same number of cycles (idempotent)
       assert final_count == initial_count
     end
   end