feat: add action-item copy and menu-bar quick control

[ottomansky]

Summary

• add reusable action-item handoff in three formats: full context, concise, and Markdown checklist
• support selecting and copying several visible action items at once, including completed items, with a focused bulk-copy bar and Command-Shift-C shortcut
• add a Start in menu bar preference so Scout can open without showing its full window
• upgrade the menu-bar panel with status, urgent action count, upcoming runs, guarded Run now controls, settings, folder, wake-schedule, and quit actions
• add restrained hover, selection, copy-feedback, and panel animations with Reduce Motion support
• add tooltips and accessibility labels without adding persistent visual clutter
• document the updated handoff and menu-bar workflows

Why

Scout already builds useful agent-ready context, but copying it previously required launching Claude and worked one item at a time. This makes the handoff portable to any agent, supports lightweight planning across several items, and keeps Scout fully useful as a compact menu-bar app.

Verification

• xcodebuild -scheme Scout -destination 'platform=macOS' build
• xcodebuild -scheme Scout -destination 'platform=macOS' test — 431 tests passed, 0 failed
• built app version verified as 0.9.1
• git diff --check

Notes

The menu-bar UI keeps secondary actions icon-only with hover help, while primary actions retain visible labels. Animations honor the system Reduce Motion setting. The build continues to emit pre-existing Swift concurrency warnings in unrelated services.