Add 'Add to contacts' feature

Toolbar More menu now saves sender to Contact Manager with green
success toast or grey 'Already in contacts' toast for duplicates.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

.gitignore

@@ -15,3 +15,10 @@ desktop.ini
 
 # Node (if added later)
 node_modules/
+
+# Local scripts
+push.bat
+push.ps1
+
+# Claude Code local settings (machine-specific)
+.claude/settings.local.json