Charter v62: one copy of the instructions in a worktree, and a shorter charter

• A session in its worktree loads the project's instructions once (#416, reported by
  rogue-trader's squad). Until now, the first Read, Edit or Write in a worktree also loaded that
  worktree's copy of CLAUDE.md, beside the main checkout's: about 48k tokens more per session in
  rogue-trader, and again after each compaction. The installer now writes Claude Code's
  claudeMdExcludes into .claude/settings.local.json for each worktree's CLAUDE.md,
  .claude/CLAUDE.md and .claude/rules/, and keeps the project's own entries; a CLAUDE.md in
  a worktree's subdirectory still loads. --check verifies the entries, and the uninstaller
  removes them.
• The charter's italic notes give a rule's reason, not the story of its incident (#417, the
  CEO's decision). The 13 notes that only told an incident go, and 20 others keep only their
  reason, in a sentence. No rule changes. The charter is about 700 words shorter, and the README
  says that each rule comes with its reason.
• Upgrading from v61: nothing to do by hand, since the installer writes the setting. Restart
  the three sessions, so that each loads the shorter charter and starts with the setting.