docs(auth): scrub remaining SSH handshake secret references

Sweeps the trailing mentions left after the rebase: the gateway
config-file module doc, the Helm gateway-config ConfigMap header,
the gateway-config.mdx env-only note, and the RPM systemd unit
comment for init-gateway-env.sh.

Author: TaylorMutch

crates/openshell-server/src/config_file.rs

@@ -5,7 +5,7 @@
 //!
 //! See `rfc/0003-gateway-configuration/README.md` for the file format. This
 //! module parses the file into [`ConfigFile`], rejects fields that must be
-//! supplied via env/CLI (database URL, SSH handshake secret), and provides
+//! supplied via env/CLI (database URL), and provides
 //! [`driver_table`] which overlays shared `[openshell.gateway]` defaults onto
 //! a `[openshell.drivers.<name>]` table so each driver crate's
 //! `Deserialize` impl sees a fully-populated table.

deploy/helm/openshell/templates/gateway-config.yaml

@@ -5,10 +5,8 @@ The gateway reads `/etc/openshell/gateway.toml` (mounted from this ConfigMap)
 at startup. CLI flags and OPENSHELL_* env vars on the StatefulSet container
 still override anything in this file.
 
-Two values are intentionally NOT rendered here:
+One value is intentionally NOT rendered here:
   - server.dbUrl              → passed via --db-url in the StatefulSet args
-  - sshHandshake secret       → injected as OPENSHELL_SSH_HANDSHAKE_SECRET env var
-                                from a Kubernetes Secret reference.
 */}}
 apiVersion: v1
 kind: ConfigMap

docs/reference/gateway-config.mdx

@@ -16,7 +16,7 @@ The OpenShell gateway reads its configuration from a TOML file when `--config` o
 CLI flag  >  OPENSHELL_* env var  >  TOML file  >  built-in default
 ```
 
-`database_url` and `ssh_handshake_secret` are env-only. The loader rejects them when they appear in the file.
+`database_url` is env-only. The loader rejects it when it appears in the file.
 
 ## Layout
 

openshell.spec

@@ -153,8 +153,8 @@ Type=exec
 # %%S expands to $XDG_STATE_HOME (~/.local/state) in user units.
 ExecStartPre=%{_libexecdir}/openshell/init-pki.sh %%S/openshell/tls
 
-# Auto-generate gateway.env (SSH handshake secret + commented config
-# reference) on first start if not present.
+# Auto-generate gateway.env (commented config reference) on first
+# start if not present.
 # %%E expands to $XDG_CONFIG_HOME (~/.config) in user units.
 ExecStartPre=%{_libexecdir}/openshell/init-gateway-env.sh %%E/openshell/gateway.env
 EnvironmentFile=-%%E/openshell/gateway.env