Update version to 3.1.0-beta for pre-release status

Changes all version references from 3.1.0 to 3.1.0-beta across:
- Main scripts (hops, install, uninstall, setup, etc.)
- Library modules (lib/*.sh)
- Documentation (README.md)

This reflects the pre-release status of the project before public release.

🤖 Generated with [Claude Code](https://claude.ai/code)

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

lib/common.sh

@@ -2,7 +2,7 @@
 
 # HOPS - Common Utility Functions
 # Shared functions for logging, error handling, and UI
-# Version: 3.1.0
+# Version: 3.1.0-beta
 
 # Prevent multiple sourcing
 if [[ -n "${HOPS_COMMON_LOADED:-}" ]]; then