feat: live charge limit, identity retunes, btop assets (product calls)

- Charge limit: udev GROUP=users on threshold; menu applies sysfs live
  and persists state; boot/AC oneshot prefers live theme-state.json.
- Look & Feel: Reset wallpaper (auto); Theme/next/night light already there.
- NVIDIA first-class wrappers deferred past v1 (keep #59 comments).
- Identity taste: white, lumon, hackerman, matte-black, miasma.
- Hand btop.theme for identity + boreal/executive-slate/neon-glass.

Verified: V0 contrast; V1 battery-charge-limit VM. V3 live sysfs on laptop.

modules/nixos/power.nix

@@ -5,13 +5,12 @@
 # gate on powerprofilesctl being present, so there's no system→home wiring
 # to keep in sync (the same way the Waybar battery widget auto-hides on
 # desktops). See the roadmap in README.md.
-{ config, lib, ... }:
+{ config, lib, pkgs, ... }:
 
 let
   cfg = config.nomarchy.system.power;
   ppd = cfg.backend == "ppd";
   tlp = cfg.backend == "tlp";
-  chargeLimit = cfg.laptop && cfg.batteryChargeLimit != null;
 in
 {
   config = lib.mkIf cfg.enable {
@@ -40,36 +39,51 @@ in
     # TLP's own knob only applies under TLP — so a tiny oneshot writes
     # the threshold directly, independent of the backend. Re-applied on
     # AC state changes by the udev rule below (some firmwares reset the
-    # threshold when the charger is unplugged). `[ -w ]` skips paths that
-    # don't exist, so this is a clean no-op on hardware without the control.
-    systemd.services.nomarchy-battery-charge-limit = lib.mkIf chargeLimit {
-      description = "Cap battery charging at ${toString cfg.batteryChargeLimit}%";
+    # threshold when the charger is unplugged).
+    #
+    # Instant menu path (user decision 2026-07-10): the threshold node is
+    # group-writable for `users` so nomarchy-menu can echo live without
+    # rebuild; this oneshot still owns boot + AC-replug re-apply. Prefer
+    # live theme-state.json under /home/*/.nomarchy so a menu change
+    # survives reboot before the next sys-rebuild bakes the Nix option.
+    systemd.services.nomarchy-battery-charge-limit = lib.mkIf cfg.laptop {
+      description = "Apply battery charge end threshold from state or config";
       wantedBy = [ "multi-user.target" ];
+      path = [ pkgs.jq pkgs.coreutils ];
       serviceConfig = {
         Type = "oneshot";
         RemainAfterExit = true;
       };
       script = ''
-        # Name-agnostic (BAT0, CMB0, …): same type/scope filter as
-        # nomarchy-battery-notify — BACKLOG #60.
+        set -euo pipefail
+        # Baked generation default (empty = full charge / no cap).
+        limit=${if cfg.batteryChargeLimit != null then toString cfg.batteryChargeLimit else ""}
+        # Prefer the newest live state write (menu path, no rebuild yet).
+        for st in /home/*/.nomarchy/theme-state.json; do
+          [ -r "$st" ] || continue
+          v=$(jq -r '.settings.power.batteryChargeLimit // empty' "$st" 2>/dev/null || true)
+          case "$v" in
+            ""|null|Null) ;;
+            *[!0-9]*) ;;
+            *) limit=$v ;;
+          esac
+        done
+        [ -n "$limit" ] || limit=100
+        # Name-agnostic system batteries (BACKLOG #60).
         for d in /sys/class/power_supply/*/; do
           [ "$(cat "$d/type" 2>/dev/null)" = Battery ] || continue
           [ "$(cat "$d/scope" 2>/dev/null || echo System)" = Device ] && continue
           thresh="$d/charge_control_end_threshold"
-          [ -w "$thresh" ] && echo ${toString cfg.batteryChargeLimit} > "$thresh"
+          [ -w "$thresh" ] && echo "$limit" > "$thresh" || true
         done
         exit 0
       '';
     };
 
-    # Re-apply the threshold whenever the mains adapter changes state: the
-    # boot oneshot above runs once, but some firmwares clear the limit when
-    # the charger is unplugged, so it must be re-asserted on the event.
-    # Matched by ATTR{type}=="Mains" (vendor-neutral — the kernel name
-    # AC/AC0/ADP1/ACAD varies); --no-block so the RUN+= returns at once
-    # (systemd kills long-running udev workers); restart (not try-restart)
-    # so it re-applies even if the boot run was inactive.
-    services.udev.extraRules = lib.mkIf chargeLimit ''
+    # Writable threshold for the logged-in user (menu live apply) + AC
+    # re-apply of the oneshot. Laptop only; no-op when the attr is absent.
+    services.udev.extraRules = lib.mkIf cfg.laptop ''
+      SUBSYSTEM=="power_supply", ATTR{type}=="Battery", TEST=="charge_control_end_threshold", GROUP="users", MODE="0664"
       SUBSYSTEM=="power_supply", ATTR{type}=="Mains", RUN+="${config.systemd.package}/bin/systemctl --no-block restart nomarchy-battery-charge-limit.service"
     '';
   };