feat: add metrics for compartments

[t0mmylam]

New metrics:

• skyhook_rollout_matched_nodes - Number of nodes matched by compartment selector
• skyhook_rollout_ceiling - Maximum nodes allowed in progress simultaneously
• skyhook_rollout_in_progress - Current nodes in progress
• skyhook_rollout_completed - Nodes completed in compartment
• skyhook_rollout_progress_percent - Completion percentage (0-100)
• skyhook_rollout_current_batch - Current batch number
• skyhook_rollout_consecutive_failures - Consecutive batch failures
• skyhook_rollout_should_stop - Binary flag indicating if rollout should stop

Labels: skyhook_name, policy_name, compartment_name, strategy

Features:

• Metrics integrated into existing reset-then-set reconciliation flow
• Automatic cleanup on Skyhook deletion
• Works in legacy mode (policy_name=legacy, compartment_name=__default__)
• Label naming follows existing conventions (_name suffix for resource identifiers)

Testing:

• Added rollout metrics checks to simple-skyhook e2e test
• Added cleanup verification to delete-skyhook e2e test