Add launchers.<cmd>.sharedDirs: share a state-dir directory between launchers
Launchers with different ids share nothing, which is right for logins but
not for Claude's projects (sessions and memory) or Codex's memories. A
shared dir is a managed symlink to the other launcher's copy, created on
demand so the link holds whichever launcher starts first, and removed with
the declaration while the data stays.
Add claude.mcpServers: MCP servers loaded with --mcp-config
The flag is variadic, so it goes first and --settings always follows it;
otherwise a prompt after it would be read as another config file. Logins
stay in the account.
Add claude.plugins: plugin directories loaded with --plugin-dir
Add packages: tools on every launcher's PATH
Add companions: every launcher of an environment callable from its sessions