Remove Plymouth, add quiet boot params, add cpu-performance module

Agent-Logs-Url: https://github.com/naturallaw777/staging_alpha/sessions/eda71495-cd38-4408-8d3b-b9d793f6445f

Co-authored-by: naturallaw777 <99053422+naturallaw777@users.noreply.github.com>

modules/core/cpu-performance.nix

@@ -0,0 +1,52 @@
+# ── modules/core/cpu-performance.nix ──────────────────────────────────────────
+# Forces all CPU cores to run at maximum frequency on node and server_plus_desktop
+# roles. Desktop-only installs retain normal OS power management behaviour.
+#
+# Three layers:
+#   1. power-profiles-daemon disabled  — removes the GNOME power profile picker;
+#                                        no user can switch profiles
+#   2. cpufreq performance governor    — pins every core to max frequency via
+#                                        kernel, enforced at boot by a oneshot unit
+#   3. systemd oneshot enforcement     — belt-and-suspenders; applies the governor
+#                                        after every boot even if module loads late
+{ config, lib, pkgs, ... }:
+
+{
+  config = lib.mkIf (!config.sovran_systemsOS.roles.desktop) {
+
+    # ── Layer 1: disable power-profiles-daemon ───────────────────────────────
+    # This removes the power-profile switcher from GNOME Settings entirely.
+    services.power-profiles-daemon.enable = false;
+
+    # ── Layer 2: set cpufreq governor to performance ─────────────────────────
+    # Pins all cores to max frequency. Works on Intel (intel_pstate) and AMD
+    # (amd-pstate / acpi-cpufreq) alike.
+    powerManagement.cpuFreqGovernor = "performance";
+
+    # ── Layer 3: enforce at boot via systemd oneshot ─────────────────────────
+    # Belt-and-suspenders: ensures the governor is applied after every boot even
+    # if the kernel module loads late.
+    systemd.services.cpu-performance = {
+      description = "Set CPU governor to performance on all cores";
+      wantedBy    = [ "multi-user.target" ];
+      after       = [ "systemd-modules-load.service" ];
+      serviceConfig = {
+        Type            = "oneshot";
+        RemainAfterExit = true;
+      };
+      script = ''
+        found=0
+        for gov in /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor; do
+          if [ -w "$gov" ]; then
+            echo performance > "$gov"
+            found=1
+          fi
+        done
+        if [ "$found" -eq 0 ]; then
+          echo "cpu-performance: no writable cpufreq governors found (VM or unsupported hardware)" >&2
+        fi
+      '';
+    };
+
+  };
+}

modules/modules.nix

@@ -15,6 +15,7 @@
     ./core/legacy-cleanup.nix
     ./core/remote-deploy.nix
     ./core/no-sleep.nix
+    ./core/cpu-performance.nix
 
     # ── Always on (no flag) ───────────────────────────────────
     ./php.nix