Normalize Nix module formatting and update flake.lock

Consistently format module argument blocks and convert aligned
package comments to inline comments. Trim trailing whitespace and
minor layout tweaks across modules. Bump opencode rev, narHash and
lastModified in flake.lock and remove the original dev ref.

modules/power.nix

@@ -1,6 +1,11 @@
 # modules/power.nix
 # Power management for desktop: CPU governor control, power profiles
-{ config, pkgs, lib, ... }:
+{
+  config,
+  pkgs,
+  lib,
+  ...
+}:
 
 {
   # ═══════════════════════════════════════════════════════════════