Redesign both Issues and My Issues headers with Linear-style layout:
- Left: scope pill buttons (All/Members/Agents for Issues; Assigned/Created/My Agents for My Issues)
- Right: compact icon buttons for Filter, Display, and View toggle
- Selected scope has accent background, all buttons use consistent outline variant
- Filter active indicator uses brand-colored dot
- Tooltips on all buttons with 500ms global delay
- Remove New Issue button and issue count from headers
- Scope selection persisted to localStorage
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
8719e2cedd