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.

themes/miasma.json

@@ -16,7 +16,7 @@
     "accentAlt": "#bb7744",
     "good": "#5f875f",
     "warn": "#b36d43",
-    "bad": "#685742"
+    "bad": "#8b5a4a"
   },
   "border": {
     "active": "accent",