feat(power): suspend-then-hibernate 1h on battery (#115)

Human decision: 1h delay, battery only, Preferences enable/disable.
Wire systemd suspend-then-hibernate + HibernateDelaySec=1h +
HibernateOnACPower=false when settings.power.suspendThenHibernate is on
and boot.resumeDevice is set. Lid: s2h undocked, plain suspend on AC.
nomarchy-suspend for hypridle + Power menu (live state). LUKS unlock
before encrypted hibernate so s2h→disk is not double-password.
state-bridges assert the policy; HARDWARE-QUEUE #115 + suggested order.

V1: nix flake check --no-build. V3: bag-carry on hardware.

README.md

@@ -258,7 +258,7 @@ two tables below are split along exactly that line.
 | `nomarchy.batteryNotify.enable` | `true` | Low-battery toasts at the bar's thresholds — 25% low, 10% critical (stays up until dismissed); silent no-op on machines without a battery |
 | `nomarchy.dockAudio.enable` | `true` | On a fresh external-monitor plug, PipeWire/WirePlumber are reprobed after hardware settles and the highest-priority available HDMI/DP/USB sink becomes default, with a toast and journal result. A later manual speaker choice sticks until the next physical plug; unplug falls back to built-in. Manual route: System › Audio |
 | `nomarchy.firstBootWelcome.enable` | `true` | One dismissible “you're set” toast on the first session (SUPER+M / SUPER+T / SUPER+? + network pointer); marker is `settings.firstBootShown` in the flake checkout |
-| `nomarchy.idle.enable` | `true` | hyprlock + hypridle (idle lock 5 min, display off 10, suspend 15 min — battery-only) |
+| `nomarchy.idle.enable` | `true` | hyprlock + hypridle (idle lock 5 min, display off 10, suspend 15 min — battery-only; uses `nomarchy-suspend` so suspend-then-hibernate applies when enabled) |
 | `nomarchy.idle.fingerprint` | `false` | Unlock the lock screen with a fingerprint as well as the password, and say so on the input field. Set it alongside `nomarchy.hardware.fingerprint.pam` in system.nix: hyprlock is configured from Home Manager, which cannot read the NixOS option — and hyprlock does **not** take a fingerprint through PAM at all (its PAM stack runs only on submit), so it uses its own fprintd backend that this switch turns on |
 | `nomarchy.yazi.enable` | `true` | yazi TUI file manager, themed + curated plugins |
 | `nomarchy.osd.enable` | `true` | swayosd on-screen display for volume/brightness/mute |
@@ -302,6 +302,7 @@ option, e.g. `services.easyeffects.enable = lib.mkForce false;` — see
 | `nomarchy.system.power.laptop` | `false` | Marks a laptop, gating battery-only features; the installer sets it when a battery is present. Clamshell uses logind's `HandleLidSwitchDocked=ignore`; the desktop additionally holds a low-level lid-switch inhibitor across dock/undock, releasing only after the internal panel is restored and the lid opens. Normal future undocked lid-close suspend remains enabled |
 | `nomarchy.system.power.thermal.enable` | `false` | thermald (Intel-only); the installer enables it on a GenuineIntel CPU |
 | `nomarchy.system.power.batteryChargeLimit` | `null` | Stop charging at this % (e.g. `80`) where the hardware supports it; needs `power.laptop` |
+| `nomarchy.system.power.suspendThenHibernate` | `true` (state) | On battery, suspend falls through to hibernate after **1 hour** (`suspend-then-hibernate` + `HibernateDelaySec=1h`; never while on AC). Needs a hibernate resume path (`boot.resumeDevice`). Toggle: System › Preferences › **Suspend then hibernate** (`settings.power.suspendThenHibernate`; system rebuild for logind lid policy). Idle and the Power menu use `nomarchy-suspend` (live state). |
 | `nomarchy.hardware.intel.enable` | `false` | Intel enablement above nixos-hardware (GuC/HuC firmware via `i915.enable_guc=3` — `.guc` toggles just that; the installer unsets it on `xe`-driver GPUs); the installer sets it on an Intel CPU/GPU |
 | `nomarchy.hardware.intel.computeRuntime` | `false` | Opt-in: Intel GPU compute — OpenCL/Level-Zero (`intel-compute-runtime`) + oneVPL (`vpl-gpu-rt`) |
 | `nomarchy.hardware.amd.enable` | `false` | AMD enablement above nixos-hardware (amd-pstate EPP + radeonsi VA-API, each toggleable via `.pstate` / `.vaapi`); installer-set on an AMD CPU/GPU |