294c377c0c
When HERMES_ROOT was added for Nix-bundled TUI support, the fallback was set to os.getcwd(). This overrode the TUI's own import.meta.dirname resolution, so launching `hermes --tui` from outside the repo caused the gateway client to look for venv/bin/python relative to the user's working directory instead of the repo root. Use PROJECT_ROOT (resolved from the source file location) as the fallback, which is stable regardless of where the command is invoked.