Add session eject feature and terminal UX improvements

- Add eject button for tmux sessions (keeps tmux running, removes from Spiceflow)
- Add refresh button to session settings for all providers
- Improve terminal controls: larger buttons, more zoom levels (50-150%), copy selection, paste clipboard, enter key
- Fix session navigation: properly reload when switching between sessions
- Update tmux screen presets to larger dimensions (fullscreen 260x48, desktop 120x48, landscape 80x24)
- Add testing documentation to CLAUDE.md
- Refactor E2E tests to use API-based cleanup

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

.gitignore

@@ -40,3 +40,6 @@ Thumbs.db
 
 # PWA
 client/dev-dist/
+
+# Test results
+e2e/test-results/