### System details

- Omarchy 4.0.4-1 (also present on `quattro` at 821ae58)
- MacBookPro16,2 (Intel T2), kernel 7.2.7-arch1-Watanare-T2-2-t2
- brightnessctl 0.5.1-3, keyboard LED `:white:kbd_backlight` (max 14660)

### What happened

After unlocking, the keyboard backlight sometimes stays at 0 instead of coming back to the level it had before the lock. Once that happens, every later unlock also restores 0, until the level is changed by hand.

### What was expected

Unlocking restores the keyboard backlight to the level it had before the screen locked.

### Cause

`omarchy-brightness-keyboard off` saves the current level and then sets 0. It saves every time it runs, including when the light is already 0:

```bash
# bin/omarchy-brightness-keyboard:28
if [[ $direction == "off" ]]; then
  brightnessctl -sd "$device" set 0 >/dev/null
```

The lock screen can run it more than once during a single lock. `runBlank()` starts `blankProcess` (`omarchy-brightness-keyboard off; omarchy-brightness-display off`) whenever `idleBlankTimer` fires. That timer is re-armed while the screen is already blank:

- `onAuthenticatingPasswordChanged` → `armBlankTimer()` after each password attempt (for example a mistyped password)
- `idleBlankTimer.onTriggered` → `armBlankTimer()` when a countdown frozen by suspend fires after resume

Each extra blank runs `off` again with the light already at 0, which saves 0 over the real level. On unlock, `omarchy-system-wake` runs `omarchy-brightness-keyboard restore`, which restores that 0.

The display has no such problem, because `omarchy-brightness-display off` uses DPMS and saves nothing.

### Steps to reproduce

Reproduced directly with the scripts, no lock needed:

```bash
D=':white:kbd_backlight'   # or any *kbd_backlight* LED
S=$XDG_RUNTIME_DIR/brightnessctl/leds/$D
brightnessctl -q -d "$D" set 40%
omarchy-brightness-keyboard off;  cat "$S"   # 5864  (the 40% level, saved)
omarchy-brightness-keyboard off;  cat "$S"   # 0     (overwritten)
omarchy-brightness-keyboard restore
brightnessctl -d "$D" get                    # 0, expected 5864
```

Through the lock screen: set the keyboard backlight to a nonzero level, lock, wait 5 seconds for the blank, then enter a wrong password and wait another 5 seconds. Unlock. The keyboard backlight stays off.

### Suggested fix

Don't save when the light is already off, so a repeated `off` keeps the level saved by the first one:

```bash
if [[ $direction == "off" ]]; then
  if (( $(brightnessctl -d "$device" get) > 0 )); then
    brightnessctl -sd "$device" set 0 >/dev/null
  fi
  exit 0
```

One edge case: if the user turned the backlight off themselves after an earlier save, `restore` brings back that older level instead of 0. To keep "off" when the user chose off, `blankProcess` could skip the keyboard when `displaysBlank` is already true, so it runs `off` only once per blank.