chore: bulk-commit chore-only sweep (1 flake.lock)

Part of the 2026-04-17 estate-wide chore sweep. Files staged with explicit paths; only files classified as chore (workflows, machine-readable, bot_directives, lockfiles) were included.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: hyperpolymath