test(progress-tracker): add batch_complete_module edge case tests (fixes #642)

[lmduy2612]

Closes #642.

Summary of Changes

Adds comprehensive edge-case test coverage for batch_complete_module in contracts/progress-tracker:

• Batch size of 1: verifies completing a single module in a batch sets the correct bit in modules_completed_bitmap and increments progress (test_batch_complete_module_batch_size_one_works_like_single).
• All modules in course: verifies submitting a batch containing all modules in the course correctly sets all bitmap bits (0b111) (test_batch_complete_module_all_modules_in_course_marks_all_complete).
• Duplicate module IDs in batch: verifies that duplicate module IDs within the batch are rejected and panic with "module already completed" (test_batch_complete_module_rejects_duplicate_within_batch).
• Partial failure rollback: verifies that if any module in the batch fails, the entire transaction reverts and no partial module completions persist (test_batch_complete_module_reverts_all_on_partial_failure).

Verification

• cargo test --test progress_tests test_batch_complete_module: 11/11 tests pass.
• Adheres strictly to project coding standards and test conventions.