Add charging indicator and pacman package, bump to 1.1.0

- Show charge/discharge power in watts, a battery graphic with charge
  bolt, a power history graph and the estimated time until full or
  remaining (respecting the 80 % charge limit) in the app, the panel
  widget, its tooltip and `predatorctl status`
- Add packaging/arch/PKGBUILD that builds a pacman package; the kernel
  module ships as DKMS source and is rebuilt for every kernel
- Bump version to 1.1.0

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

predator_control/hardware.py

@@ -247,7 +247,7 @@ def set_lightbar(mode="static", color=(0, 200, 255), brightness=200, speed=5, di
 
 # --------------------------------------------------------------- Battery
 
-def battery():
+def battery(limit_80=False):
     bat = next(iter(glob.glob("/sys/class/power_supply/BAT*")), None)
     ac = next((p for p in glob.glob("/sys/class/power_supply/*")
                if _read(p + "/type") == "Mains"), None)
@@ -268,6 +268,19 @@ def battery():
         "cycles": _read_int(bat + "/cycle_count"),
         "health": round(100.0 * full / design, 1) if full and design else None,
     })
+    # remaining time in minutes (to full while charging, to empty while discharging)
+    now = _read_int(bat + "/charge_now") or _read_int(bat + "/energy_now")
+    rate = cur if _read_int(bat + "/charge_now") is not None else pwr
+    minutes = None
+    if now is not None and full and rate:
+        rate = abs(rate)
+        if out["status"] == "Charging":
+            target = full * 0.8 if limit_80 else full
+            minutes = int(max(0, target - now) / rate * 60)
+        elif out["status"] == "Discharging":
+            minutes = int(now / rate * 60)
+    out["minutes_left"] = minutes
+    out["charging"] = out["status"] == "Charging"
     return out