feat: add styles and polish for unified session list components

- Add CSS styles for SessionCard and SessionList components
- Add responsive styles for mobile viewport
- Fix TypeScript errors (remove unused port property)
- Fix ESLint errors (remove unused imports and variables)

Refs: session-list-overhaul tasks 5-6

openspec/changes/session-list-overhaul/tasks.md

@@ -35,10 +35,10 @@
 
 ## 5. Styles and Polish
 
-- [ ] 5.1 Add CSS styles for SessionCard layout (responsive grid)
-- [ ] 5.2 Add CSS styles for action buttons (icon vs text based on viewport)
-- [ ] 5.3 Style status indicators and badges
-- [ ] 5.4 Ensure consistent spacing and typography
+- [x] 5.1 Add CSS styles for SessionCard layout (responsive grid)
+- [x] 5.2 Add CSS styles for action buttons (icon vs text based on viewport)
+- [x] 5.3 Style status indicators and badges
+- [x] 5.4 Ensure consistent spacing and typography
 - [ ] 5.5 Test responsive layout on mobile viewport
 
 ## 6. Testing and Verification
@@ -49,5 +49,5 @@
 - [ ] 6.4 Test confirmation dialogs
 - [ ] 6.5 Test empty states
 - [ ] 6.6 Test responsive layout
-- [ ] 6.7 Run TypeScript compilation
-- [ ] 6.8 Run ESLint
+- [x] 6.7 Run TypeScript compilation
+- [x] 6.8 Run ESLint