v1.51.1

Patch on top of v1.51.0 — no runtime change, CI/repo hygiene only.

Fixed

• scripts/e2e.sh status-line assertion now matches the new plain-text line (… <N>% weekly) — v1.51.0 changed the format but the test still checked the old wk segment, turning CI red.
• Untracked accidentally-committed hooks/__pycache__/*.pyc and added a Python .gitignore rule.

v1.51.0 is the substantive release (builders→Opus, worktrees + dynamic workflows on by default, plain-text status line, emoji removed). See CHANGELOG.md.