power: add sample superfreq config

modules/system/hardware/power.nix

@@ -29,7 +29,54 @@ in {
 
     hardware.acpilight.enable = false;
 
-    programs.superfreq.enable = true;
+    services.superfreq = {
+      enable = true;
+      # sample config from https://github.com/NotAShelf/superfreq#sample-configuration
+      settings = {
+        charger = {
+          # CPU governor to use
+          governor = "performance";
+          # Turbo boost setting: "always", "auto", or "never"
+          turbo = "auto";
+          # Energy Performance Preference
+          epp = "performance";
+          # Energy Performance Bias (0-15 scale or named value)
+          epb = "balance_performance";
+          # Platform profile (if supported)
+          platform_profile = "performance";
+          # Min/max frequency in MHz (optional)
+          min_freq_mhz = 800;
+          max_freq_mhz = 3500;
+          # Optional: Profile-specific battery charge thresholds (overrides global setting)
+          # battery_charge_thresholds = [40, 80]  # Start at 40%, stop at 80%
+        };
+
+        battery = {
+          governor = "powersave";
+          turbo = "auto";
+          epp = "power";
+          epb = "balance_power";
+          platform_profile = "low-power";
+          min_freq_mhz = 800;
+          max_freq_mhz = 2500;
+        };
+
+        daemon = {
+          # Base polling interval in seconds
+          poll_interval_sec = 5;
+          # Enable adaptive polling that changes with system state
+          adaptive_interval = true;
+          # Minimum polling interval for adaptive polling (seconds)
+          min_poll_interval_sec = 1;
+          # Maximum polling interval for adaptive polling (seconds)
+          max_poll_interval_sec = 30;
+          # Double the polling interval when on battery to save power
+          throttle_on_battery = true;
+          # Logging level: Error, Warning, Info, Debug
+          log_level = "Info";
+        };
+      };
+    };
     services = {
       upower = {
         enable = true;