Add node.log_level config, remove RUST_LOG from service files

Add log_level field to NodeConfig (case-insensitive, default: info).
The daemon now loads config before initializing tracing so the
configured level takes effect. RUST_LOG env var still overrides if
set.

Remove hardcoded Environment=RUST_LOG=info from systemd units and
OpenWrt procd init script — these prevented config-driven log levels
from working.

packaging/debian/fips.service

@@ -9,9 +9,6 @@ ExecStart=/usr/bin/fips --config /etc/fips/fips.yaml
 Restart=on-failure
 RestartSec=5
 
-# Logging: RUST_LOG controls verbosity.
-Environment=RUST_LOG=info
-
 # Control socket directory (/run/fips/).
 # Group-accessible so 'fips' group members can use fipsctl/fipstop.
 RuntimeDirectory=fips

packaging/openwrt-ipk/files/etc/init.d/fips

@@ -14,7 +14,6 @@ start_service() {
 
 	procd_open_instance
 	procd_set_param command "$PROG" --config "$CONFIG"
-	procd_set_param env RUST_LOG=info
 	# Respawn: restart after 5 s, give up after 5 consecutive failures within
 	# a 3600 s window, then reset the failure counter and try again.
 	procd_set_param respawn 3600 5 5

packaging/systemd/fips.service

@@ -9,9 +9,6 @@ ExecStart=/usr/local/bin/fips --config /etc/fips/fips.yaml
 Restart=on-failure
 RestartSec=5
 
-# Logging: RUST_LOG controls verbosity.
-Environment=RUST_LOG=info
-
 # Control socket directory (/run/fips/).
 # Group-accessible so 'fips' group members can use fipsctl/fipstop.
 RuntimeDirectory=fips