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>

install

@@ -8,7 +8,7 @@ install_hops() {
     set -e
 
     # Script version for update tracking
-    local SCRIPT_VERSION="3.1.0"
+    local SCRIPT_VERSION="3.1.0-beta"
     local SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
 
     # Load system utilities