docs: document HERMES_WEBUI_SETTINGS_FILE (#6433) incl. restart-to-change note

README.md

@@ -362,6 +362,7 @@ Full list of environment variables:
 | `HERMES_WEBUI_HOST` | `127.0.0.1` | Bind address (`0.0.0.0` for all IPv4, `::` for all IPv6, `::1` for IPv6 loopback) |
 | `HERMES_WEBUI_PORT` | `8787` | Port |
 | `HERMES_WEBUI_STATE_DIR` | `$HERMES_HOME/webui` (Windows default `%LOCALAPPDATA%\hermes\webui`, POSIX default `~/.hermes/webui`) | Where sessions and state are stored. **Note (upgrade):** the default now follows `HERMES_HOME` — if you previously relocated `HERMES_HOME` to a non-default base **without** setting `HERMES_WEBUI_STATE_DIR`, your WebUI state now resolves to `$HERMES_HOME/webui` instead of the old platform-default `~/.hermes/webui`. To keep using the old location, set `HERMES_WEBUI_STATE_DIR` to it (or move the directory). Installs with `HERMES_HOME` unset or at the default base are unaffected. |
+| `HERMES_WEBUI_SETTINGS_FILE` | `<state dir>/settings.json` | Optional path for this instance's WebUI settings file (sessions, workspaces and projects stay in the state directory). Read once at startup, so restart after changing it |
 | `HERMES_WEBUI_DEFAULT_WORKSPACE` | `~/workspace` | Default workspace |
 | `HERMES_WEBUI_DEFAULT_MODEL` | *(provider default)* | Optional model override; leave unset to use the active Hermes provider default |
 | `HERMES_WEBUI_PASSWORD` | *(unset)* | Set to enable password authentication |