feat(oxibadge): add timesheet review and export screen

Add the month-review screen shown after records/employees load: an
editable per-employee timesheet table with issue/rounding detection,
bulk fixes (reorder stacked punches, add lunch break, round to step),
and an export flow (single employee or all) wired to a new Rust
export_timesheet command. Split into focused components under
review/ instead of one large file, with shared i18n keys and a new
export_timesheet IPC command.

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

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

@@ -0,0 +1,33 @@
+<script lang="ts">
+  let { message }: { message: string } = $props();
+</script>
+
+{#if message}
+  <div class="toast" role="status">
+    <svg width="18" height="18" viewBox="0 0 24 24" aria-hidden="true"
+      ><circle cx="12" cy="12" r="9" /><path d="M8 12.5l2.5 2.5L16 9.5" /></svg
+    >
+    <span>{message}</span>
+  </div>
+{/if}
+
+<style>
+  .toast {
+    position: absolute;
+    left: 50%;
+    bottom: 24px;
+    transform: translateX(-50%);
+    z-index: 45;
+    display: flex;
+    align-items: center;
+    gap: 10px;
+    padding: 12px 16px;
+    border-radius: 12px;
+    background: #13221a;
+    border: 1px solid #1f4a31;
+    color: #8be0ae;
+    font-size: 14px;
+    box-shadow: 0 16px 40px rgba(0, 0, 0, 0.5);
+    white-space: nowrap;
+  }
+</style>