feat(waybar): combined power menu on the battery + profile icons

Item 36(b). Adds `nomarchy-menu powermgmt` — one flat rofi menu of power
Profile rows (→ powerprofilesctl set) + Charge limit rows (→ the same
theme-sync writer batterylimit uses), each half self-gating on its
hardware. No backend duplication; Custom charge stays in the dedicated
batterylimit picker.

Opened two ways (Bernardo's call): the Waybar battery icon AND the
power-profile icon — the profile icon's click flips from cycle → menu.
Wired in waybar.nix and all four whole-swaps (parity). Named `powermgmt`
to avoid the whole-swaps' existing `custom/powermenu` shutdown button
(→ nomarchy-menu power), which is left untouched. The granular System ▸
Power profile / Battery limit rows stay ("keep both").
nomarchy-powerprofile-cycle kept as a standalone bin, now unbound by
default.

Verified: V0 green; V1 HM built (bash -n) — powermgmt case ships, the
generated waybar-config.json wires both icons (2 hits), all four jsoncs
re-wired and still parse, shutdown buttons intact. Click→menu→apply is
V3 (queued).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

agent/HARDWARE-QUEUE.md

@@ -282,6 +282,16 @@ QA machine), the **T14s** (webcam case).
       shows a single arrow, no double; (c) on this single-monitor box,
       System › Display → pick a resolution → Back returns to System
       (not back into the same resolution list).
+- [ ] **Combined power menu** (iteration #67, item 36b) — after
+      `home-update` + relogin: clicking EITHER the Waybar battery icon OR
+      the power-profile icon opens one "Power" menu listing Profile: rows
+      + Charge limit: rows; picking a profile calls `powerprofilesctl set`
+      (verify `powerprofilesctl get` changes), picking a charge preset
+      writes `settings.power.batteryChargeLimit` (applies next rebuild).
+      The prompt shows the current profile + limit. System ▸ Power profile
+      / Battery limit still work directly; the whole-swap bars (summer-day/
+      night, executive-slate, boreal) behave the same and their shutdown
+      power-button (if present) still opens the lock/logout menu.
 
 ## AMD dev box only
 - [ ] **AMD runtime bits** — VA-API (`vainfo` → radeonsi), amd-pstate EPP