fix: remove nodejs from extended tools to prevent conflict

[schickling]

Summary

• Remove nodejs_22 from the extended tools list to prevent conflicts with system-installed nodejs

Problem

The clawdbot package bundles nodejs_22 in its extended tools (nix/tools/extended.nix), which conflicts with system-installed nodejs when both are in home.packages:

pkgs.buildEnv error: two given paths contain a conflicting subpath:
  `/nix/store/...-nodejs-24.13.0/bin/node' and
  `/nix/store/...-clawdbot-2.0.0-beta5/bin/node'

Solution

Remove nodejs_22 from the baseNames list in extended.nix. The clawdbot-gateway wrapper already references node internally via makeWrapper with $NODE_BIN, so there's no need to expose node in the user's PATH through the tools bundle.

Clawdbot continues to work correctly because:

1. The gateway uses makeWrapper to reference nodejs internally
2. pnpm is still included for any npm-related tooling needs

Fixes #15