SubTrim

Usage:
  /iR3PH6Yt                                      private path mode: source URL from SOURCE_URL/SUB_URL/NODES_URL env
  /clean?url=ENCODED_HTTPS_SUB_URL                stateless style
  /clean?key=ACCESS_TOKEN&url=ENCODED_HTTPS_SUB_URL

Behavior:
  - Only rename node names/tags.
  - Drop nodes whose region cannot be recognized.
  - Keep server/protocol/port/password/rules/DNS unchanged.