feat: add reserve_resources method for CRN capacity pre-check

[aliel]

No description provided.

[github-actions]

Failed to retrieve llama text: POST 502: Bad Gateway

[foxpatch-aleph]

The PR adds a useful reserve_resources method for CRN capacity pre-check and refactors create_vm_control_payload to use a new create_control_payload helper. However, there are two issues: (1) the original create_vm_control_payload function had a bug where it created a payload dict but returned a different dict entirely - this was silently broken before and the PR correctly fixes it; (2) there's no test coverage for the new functionality. The code quality is good and follows existing patterns.

src/aleph/sdk/utils.py (line 240): The original create_vm_control_payload function had a subtle bug: it created a payload dict but then returned a completely new dict literal (the return payload at the end was unreachable). The PR correctly fixes this by extracting the common logic into create_control_payload. This is a good refactor that fixes a latent bug.

src/aleph/sdk/client/vm_client.py (line 337): The new reserve_resources method is missing test coverage. Please add tests following the existing pattern in test_vm_client.py (e.g., test_perform_operation, test_notify_allocation). Test both success (200) and failure (503) cases.

src/aleph/sdk/client/vm_client.py (line 368): Minor: The logger format string uses %s which works but could be more explicit. Consider using str(e) for consistency with the return statement, or use .format() or f-string: logger.error("HTTP error during reserve_resources: %s", str(e))

src/aleph/sdk/client/vm_client.py (line 327): Note: The notify_allocation method doesn't have error handling for aiohttp.ClientError while reserve_resources does. Consider adding similar error handling to notify_allocation for consistency, or document why it's different.

[foxpatch-aleph]

This PR adds a well-implemented reserve_resources method for CRN capacity pre-checks. The implementation follows existing authentication patterns, the refactoring of create_vm_control_payload to use a generic helper reduces duplication, and tests cover the main success and failure scenarios. The code is clean and consistent with the codebase.

src/aleph/sdk/client/vm_client.py (line 368): Minor: The %s format specifier will call str() automatically, so str(e) is redundant. Consider simplifying to logger.error("HTTP error during reserve_resources: %s", e) for consistency with typical logging patterns.

tests/unit/test_vm_client.py (line 270): Consider adding a test for the aiohttp.ClientError exception path that returns (None, str(e)). While this mirrors the pattern in other methods like perform_operation, adding coverage would improve test completeness.