chore(motion): remove unused FlashSAC owner contract

[TATP-233]

Summary

• Remove the unused G1 FlashSAC semantic-owner fingerprint module and its dedicated contract tests.
• Preserve the Motrix Manager runtime registration assertion in the package-boundary suite.
• Replace the stale direct-runtime attribute assertions with a source-file absence check.
• Remove stale ADR evidence references to the deleted fingerprint module.
• No user-facing, backend, platform, or training behavior changes are expected; runtime code had no caller for the removed module.

Linked Work

• Issue: roadmap: tensor-only Manager-Based runtime and three-backend scope reduction #1811
• Parent roadmap: roadmap: tensor-only Manager-Based runtime and three-backend scope reduction #1811
• Roadmap declared base: main after integration branch merge: tensor-only Manager runtime and MJWarp tensor-native closeout #2044 was merged
• Milestone: none
• Base branch: main

Validation

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

Commands actually run:

uv run pytest tests/tasks/test_package_boundary.py tests/config/test_g1_motion_tracking_owners.py
uv run pytest tests/scripts/test_check_docs.py -q
make check
make test
mkdir -p /tmp/ul && TMPDIR=/tmp/ul/ make test-all
git diff --check

make test initially failed 7 Unix-socket tests with OSError: AF_UNIX path too long under the default macOS temporary-directory path. Rerunning the required final gate with a shorter TMPDIR passed. The successful make test-all result covers formatting, type checks, 1781 non-slow tests, and benchmark smoke imports.

Remote CI route:

• Base main: all current-head required checks passed. CI: https://github.com/Motphys/UniLab/actions/runs/37769809714 Docs: https://github.com/Motphys/UniLab/actions/runs/37769809778

Impact

• Backend impact: none
• Platform impact: none
• Training effect expected: no

Artifacts

• W&B: none
• benchmark result: none
• video / screenshot: none
• ONNX / checkpoint: none

Checklist

• Added or updated tests where needed
• Updated docs if behavior or workflow changed
• Linked the driving issue
• Noted any follow-up work explicitly