feat(oxibadge): add month-confirmation flow and fetch records/employees

Adds the screen after onboarding: pick a month/year (ConfirmMonth), show
loading screens while the device is queried, then download that month's
records and resolve each distinct employee's name, printing both to
stdout (debug pretty-print) before landing on the placeholder "done"
screen.

- r701: RecordIterator's boxed stream is now Send, required for it to
  cross into a Tauri command's future.
- oxibadge: load_records/load_employees commands, sharing the existing
  3-retry connect_with_retries helper. load_records uses skip_while/
  take_while on the device's newest-first stream to grab only the
  target month without walking its whole history, then a single
  collect + in-place Vec::reverse() back to chronological order.
- Shared LoadingScreen/Intro components extracted so future screens
  reuse the same look without duplicating markup/CSS.

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

oxibadge/src/routes/+page.svelte

@@ -1,25 +1,56 @@
 <script lang="ts">
   import { invoke } from '@tauri-apps/api/core';
   import { onMount } from 'svelte';
-  import { _ } from 'svelte-i18n';
+  import { _, locale } from 'svelte-i18n';
+  import { monthName } from '$lib/month';
   import Screen from '$lib/components/Screen.svelte';
   import Onboarding from '$lib/components/Onboarding.svelte';
+  import ConfirmMonth from '$lib/components/ConfirmMonth.svelte';
+  import LoadingScreen from '$lib/components/LoadingScreen.svelte';
 
-  type Step = 'loading' | 'setup' | 'done';
+  type Step = 'loading' | 'setup' | 'confirm-month' | 'loading-records' | 'loading-employees' | 'done';
 
   let step = $state<Step>('loading');
+  let selectedYear = $state(0);
+  let selectedMonth = $state(0);
+
+  const period = $derived(`${monthName($locale, selectedMonth)} ${selectedYear}`);
 
   onMount(async () => {
     const preferences = await invoke<{ host: string; port: number } | null>('load_preferences');
-    step = preferences ? 'done' : 'setup';
+    step = preferences ? 'confirm-month' : 'setup';
   });
+
+  async function loadMonth(selection: { year: number; month: number }) {
+    selectedYear = selection.year;
+    selectedMonth = selection.month;
+    step = 'loading-records';
+    try {
+      const records = await invoke('load_records', selection);
+      step = 'loading-employees';
+      await invoke('load_employees', { records });
+      step = 'done';
+    } catch (err) {
+      console.error(err);
+      step = 'confirm-month';
+    }
+  }
 </script>
 
 <Screen>
   {#if step === 'loading'}
     <p>{$_('loading')}</p>
   {:else if step === 'setup'}
-    <Onboarding onconnected={() => (step = 'done')} />
+    <Onboarding onconnected={() => (step = 'confirm-month')} />
+  {:else if step === 'confirm-month'}
+    <ConfirmMonth onstart={loadMonth} />
+  {:else if step === 'loading-records'}
+    <LoadingScreen
+      title={$_('loading_records.title')}
+      description={$_('loading_records.description', { values: { period } })}
+    />
+  {:else if step === 'loading-employees'}
+    <LoadingScreen title={$_('loading_employees.title')} description={$_('loading_employees.description')} />
   {:else}
     <p>{$_('done.message')}</p>
   {/if}