upower fork: submodule, prebuilt packaging, CI build, lock-surface charge state

- packaging/upower-souveraine submodule pinned at fork head (f18b1a4,
  souveraine/charge-type): ChargeType + PercentageTrusted on Device
- PKGBUILD.upower.prebuilt: prebuilt meson install tree, provides/
  conflicts upower, replaces stock (IgnorePkg=upower on the phone)
- ci.yml: build the fork per-arch against the aarch64 sysroot, assert
  binary arch, fold into the souveraine-{arch} pacman db
- LockSurfaceHost: charge line driven by device state, not onBattery —
  no more eternal 'Charging N%' on a topped-off pack
- docs/tasks/power-indication.md force-added past the docs/ gitignore

docs/tasks/INDEX.md

@@ -99,6 +99,7 @@
 | `souveraine-subconscious-naming.md` | 2 | pending | Clarify naming: Ani's subconscious = Aster, Souveraine agents' subconscious = Souveraine-subconscious. |
 | `quickshell-surface-package.md` | delivery | **in progress** | Split core from QuickShell surface package; safe preview/adopt installer, no automatic ii overwrite. |
 | `device-specific-quickshell-profiles.md` | delivery | scoped | Phone and laptop share the agent channel but have distinct QuickShell bodies, manifests, and packages. |
+| `power-indication.md` | delivery | scoped | Charging state, honest full detection (state not onBattery — kills "Charging 1% forever"), a PowerService singleton, and charge-aware idle policy (sleep-inhibit while charging, wake-on-charge). |
 | `footer-cleanup.md` | 3.0 | **landed** | Removed S-Ret indicator, scroll hint, posture label. Footer: Esc menu · Tab · tool hint · conv ID · ctx%. |
 | `ui-styling-cleanup.md` | 3.0 | pending | UI styling polish for cockpit/subconscious/thinking boxes — sentences run together, needs formatting and visual cleanup. |
 | `resume-timestamp-indicator.md` | 3.0 | pending | Show "User resumed conversation at HH:MM" when returning after hours of absence. Also show duration ("4 hours, 12 minutes later"). Ambient sense rendered as separate timestamp marker, not inline. |