Siddharth Balyan 4219a91df5
fix(nix): make config.yaml group-writable under addToSystemPackages (#41940)
addToSystemPackages exports HERMES_HOME system-wide and puts the hermes CLI on
interactive users' PATH, so those users (in the hermes group) share the
gateway's state — that's the option's whole purpose. But the activation script
wrote config.yaml as 0640 (group read-only), so an interactive user saving a
setting via the CLI/TUI hit:

  error: [Errno 13] Permission denied: '/var/lib/hermes/.hermes/config.yaml'

Make the mode conditional: 0660 when addToSystemPackages is set (group hermes
can write), else the previous 0640. .env stays 0640 either way — it holds
secrets, not user-facing settings. The config merge already preserves
user-added keys across rebuilds, so this simply lets interactive hermes-group
users actually make those edits.

Verified by evaluating the module's activation script for both option values:
addToSystemPackages=true -> chmod 0660, false -> chmod 0640.
2026-06-08 20:10:47 +05:30
..