Guard timed weight commit submissions

[markdavison]

Summary:

• pre-gate timed commit submissions by reading TimelockedWeightCommits
• defer when the active timed-commit bucket already has one pending commit for this hotkey
• set SDK set_weights max_attempts=1 and update tests/status logging

Tests:

• uv run --project validator pytest -q
• uv run --project validator ruff check validator/src/gm_validator/bittensor_adapter.py validator/src/gm_validator/bittensor_real.py validator/src/gm_validator/validator.py validator/tests/test_weight_status.py validator/tests/test_bittensor_real.py validator/tests/test_validator_integration.py