Share, milestones, and better navigation

• New share extension: images, text, and web pages from other apps turn into a new issue
• Milestones can now be edited, renamed, closed, reopened, and deleted
• Search and issue filter chips use theme-aware colors with significantly better contrast
• Settings navigation now reliably resets after switching tabs
• The account profile is now the first row in Settings — no more “More” tab
• New “Recommend the app” section right below the subscription
• Robust data migration: existing accounts and tokens survive the update