chore: add Ruby version and update gitignore (#22)

* chore: add .worktrees to gitignore for parallel development

* chore: add Ruby version and ignore personal Claude workflows

- Set Ruby 3.3.6 via .ruby-version (fixes native gem ABI issues)
- Ignore .claude/ and CLAUDE.md (personal workflows stay local)

Author: vishaltps

.gitignore

@@ -12,3 +12,10 @@
 .rspec_status
 
 *.gem
+
+# Git worktrees for parallel development
+.worktrees/
+
+# Claude Code personal workflows (local only)
+.claude/
+CLAUDE.md

.ruby-version

@@ -0,0 +1 @@
+3.3.6