feat(oxibadge): add settings screen for shifts, rounding and language

Add a settings screen (gear button on the month-confirmation screen)
to configure the expected shift times, the rounding step, the
interface language, and the time clock address — replacing the old
onboarding-only connection flow. Settings persist to the same
preferences.toml as the reader address, under a single load_settings/
save_settings command pair.

The review screen's "fix shifts" action now redistributes stacked
punches by nearest configured shift time instead of blind position,
and a stacked cell manually cleared down to one entry no longer
leaves a dangling empty input.

Assisted-by: Claude Sonnet 5 <noreply@anthropic.com>

oxibadge/src/lib/components/review/EmployeeHeader.svelte

@@ -1,8 +1,10 @@
 <script lang="ts">
   import { _ } from 'svelte-i18n';
-  import { LUNCH, ROUND_STEP, dayWord } from './analysis';
+  import { autofocus } from '$lib/autofocus';
+  import type { Shifts } from '$lib/shifts';
+  import { dayWord } from './analysis';
   import FixButton from './FixButton.svelte';
-  import IconButton from './IconButton.svelte';
+  import IconButton from '../IconButton.svelte';
 
   let {
     name,
@@ -17,6 +19,7 @@
     stackedCount,
     lunchCount,
     roundCount,
+    shift,
     onfixall,
     onaddlunchall,
     onroundall,
@@ -34,6 +37,7 @@
     stackedCount: number;
     lunchCount: number;
     roundCount: number;
+    shift: Shifts;
     onfixall: () => void;
     onaddlunchall: () => void;
     onroundall: () => void;
@@ -51,10 +55,6 @@
     editing = false;
   }
 
-  function autofocus(node: HTMLInputElement) {
-    node.focus();
-    node.select();
-  }
 </script>
 
 <div class="main-head">
@@ -121,7 +121,7 @@
     {#if lunchCount}
       <FixButton
         size="lg"
-        title={$_('review.add_lunch_title', { values: { start: LUNCH.start, end: LUNCH.end } })}
+        title={$_('review.add_lunch_title', { values: { start: shift.out1, end: shift.in2 } })}
         onclick={onaddlunchall}
       >
         {#snippet icon()}
@@ -139,7 +139,7 @@
             ><circle cx="12" cy="13" r="8" /><path d="M12 9v4l2.5 2.5M10 2h4" /></svg
           >
         {/snippet}
-        {$_('review.round_all', { values: { step: ROUND_STEP, days: dayWord(roundCount, $_) } })}
+        {$_('review.round_all', { values: { step: shift.round_step_min, days: dayWord(roundCount, $_) } })}
       </FixButton>
     {/if}
     <div class="seg" role="group" aria-label={$_('review.day_filter_aria')}>