chore(deps): adopt unilab-rl 1.4.6 sac naming

[TATP-233]

Summary

• Update the default and ROCm unilab-rl dependency profiles and locks to 1.4.6.
• Rename UniLab-owned FastSAC references to SAC with no compatibility layer.
• Switch SAC dispatch and tests to uni_rl.algos.sac / SACLearner.
• Change the SAC log name and default directory from fast_sac to sac.
• Update the bilingual user and architecture docs affected by the rename.
• Make the MPS fail-closed runner test deterministic on macOS by mocking its intended Linux platform prerequisite.
• Resolve conflicts with feat: remove retired task owners and WarpSAC #2072 by preserving its retired-task and WarpSAC removals while retaining this PR's SAC-only rename.

Linked Work

• Issue: Work: adopt unilab-rl 1.4.6 SAC naming #2073
• Parent roadmap (when applicable): N/A
• Roadmap declared base (when applicable): N/A
• Milestone: N/A
• Base branch: main

Validation

• make test-all passed on the final local head before this PR was updated
• Additional task-specific validation listed below

Commands actually run:

uv lock
uv lock --check
uv run pytest tests/algos/test_offpolicy_dp_sync.py tests/algos/test_offpolicy_double_buffer_runner.py tests/scripts/test_train_scripts.py tests/utils/test_experiment_tracking.py --deselect 'tests/algos/test_offpolicy_double_buffer_runner.py::test_cuda_process_sharing_request_fails_before_env_materialization[sac]' --deselect 'tests/algos/test_offpolicy_double_buffer_runner.py::test_cuda_process_sharing_request_fails_before_env_materialization[flashsac]' --deselect 'tests/algos/test_offpolicy_double_buffer_runner.py::test_cuda_process_sharing_request_fails_before_env_materialization[warpsac]'
# pre-merge focused run: 81 passed

make check
# passed

make test
# exposed an existing macOS MPS test platform-mock issue

uv run pytest tests/algos/test_offpolicy_double_buffer_runner.py::test_cuda_process_sharing_request_fails_before_env_materialization --basetemp=/tmp/unilab-pytest-focused
# 3 passed

uv run pytest tests/scripts/test_rocm_dependency_profile.py tests/scripts/test_torch_cuda_source.py
# 4 passed

TMPDIR=/tmp PYTEST_ADDOPTS='--basetemp=/tmp/unilab-pytest-all' make test-all
# pre-merge final gate passed

TMPDIR=/tmp PYTEST_ADDOPTS='--basetemp=/tmp/unilab-pytest-all-merged' make test-all
# post-conflict-resolution final gate passed on merge commit e0d01703:
# 1788 passed, 58 skipped, 488 deselected; benchmark smoke 34/34 module and 35/35 script imports

An initial full run was interrupted after the macOS-only MPS prerequisite assertion. The missing Linux platform mock was fixed in this PR. After merging current main (#2072), the complete gate above passed again on the final head.

Remote CI route:

• Base main: CI passed and Docs passed on head e0d01703.

Impact

• Backend impact: none
• Platform impact: both (default and ROCm dependency profiles)
• Training effect expected: yes (SAC runtime import and canonical log name become sac; no compatibility layer)

Artifacts

• W&B: N/A
• benchmark result: benchmark smoke output included in validation
• video / screenshot: N/A
• ONNX / checkpoint: N/A

Checklist

• Added or updated tests where needed
• Updated docs if behavior or workflow changed
• Linked the driving issue
• Noted any follow-up work explicitly (none)