feat: Remove deprecated test files and enhance documentation for version 3.3.0 "Nexus Infinitum"

- Deleted obsolete test files: test_mime.go, test_mime_integration.go, and xmpp_client_upload_diagnosis.ipynb.
- Updated README.md to reflect the new version 3.3.0 "Nexus Infinitum" and its features.
- Added comprehensive release notes for version 3.3.0 detailing major enhancements and installation instructions.
- Introduced cleanup script to remove development artifacts while preserving production files.

install-manager.sh

@@ -30,7 +30,7 @@ log_step() { echo -e "${CYAN}[STEP]${NC} $1"; }
 show_main_menu() {
     clear
     echo -e "${MAGENTA}╔════════════════════════════════════════════════════════════════╗${NC}"
-    echo -e "${MAGENTA}║${NC}         ${BLUE}HMAC File Server 3.2 'Tremora del Terra'${NC}         ${MAGENTA}║${NC}"
+    echo -e "${MAGENTA}║${NC}         ${BLUE}HMAC File Server 3.3 'Nexus Infinitum'${NC}         ${MAGENTA}║${NC}"
     echo -e "${MAGENTA}║${NC}              ${CYAN}Universal Installation Manager${NC}              ${MAGENTA}║${NC}"
     echo -e "${MAGENTA}╚════════════════════════════════════════════════════════════════╝${NC}"
     echo ""