chore: enforce Black formatting in pre-commit and CI to prevent drift

[mrveiss]

Summary

89 Python files drifted from Black formatting standards and were discovered via CI check (2026-04-03). The files were reformatted manually in commit `76ac6c7e8`. Without enforcement, this will recur.

Discovery

Found during routine session — Black `--check` on `autobot-backend/` and `autobot-slm-backend/` reported 89 files needing reformat. No pre-commit hook was preventing the drift.

Proposed Fix

1. Verify `.pre-commit-config.yaml` includes Black with auto-format on staged files
2. Ensure all developers run `pre-commit install` after cloning
3. Confirm CI pipeline runs `black --check` as a blocking step
4. Consider adding `isort --profile black` check alongside Black

Acceptance Criteria

• Pre-commit hook runs Black on staged `.py` files before every commit
• CI `black --check` step is present and blocking
• No files fail `black --check` after changes are applied

[github-actions]

PR #3409 (merged to Dev_new_gui) references this issue with a close keyword.

style: apply Black formatting to 89 Python files (#3408)

If this issue is fully resolved, close it manually. If work remains, no action is needed.