feat: Enter to save, Escape to discard, auto-save on unit/group selection

- selectUnit/selectGroup now async; call autoSaveCurrentForm before switching
- Enter in any form field (except textarea) triggers save
- Escape restores form to snapshot (discards unsaved changes)
- discardUnitForm/discardGroupForm helpers for snapshot restore

src/routes/admin/+page.svelte

@@ -214,7 +214,9 @@
   });
 
   // ── Selection ────────────────────────────────────────────────────────────────
-  function selectUnit(unit: Unit) {
+  async function selectUnit(unit: Unit) {
+    const ok = await autoSaveCurrentForm();
+    if (!ok) return;
     selectedItem = { type: 'unit', id: unit.id };
     unitForm = { ...unit };
     unitFormSnapshot = { ...unit };
@@ -226,7 +228,9 @@
     formSuccess = null;
   }
 
-  function selectGroup(group: Group) {
+  async function selectGroup(group: Group) {
+    const ok = await autoSaveCurrentForm();
+    if (!ok) return;
     selectedItem = { type: 'group', id: group.id };
     groupForm = { ...group };
     groupFormSnapshot = { ...group };
@@ -446,6 +450,40 @@
     await loadData();
   }
 
+  // ── Keyboard shortcuts for forms ─────────────────────────────────────────────
+  function discardUnitForm() {
+    unitForm = { ...unitFormSnapshot };
+    unitFieldError = null;
+    formError = null;
+    formSuccess = null;
+  }
+
+  function discardGroupForm() {
+    groupForm = { ...groupFormSnapshot };
+    groupFieldError = null;
+    formError = null;
+    formSuccess = null;
+  }
+
+  function onUnitFormKeydown(e: KeyboardEvent) {
+    // Don't intercept Enter inside textareas
+    if (e.key === 'Enter' && (e.target as HTMLElement).tagName !== 'TEXTAREA') {
+      e.preventDefault();
+      saveUnit();
+    } else if (e.key === 'Escape') {
+      discardUnitForm();
+    }
+  }
+
+  function onGroupFormKeydown(e: KeyboardEvent) {
+    if (e.key === 'Enter' && (e.target as HTMLElement).tagName !== 'TEXTAREA') {
+      e.preventDefault();
+      saveGroup();
+    } else if (e.key === 'Escape') {
+      discardGroupForm();
+    }
+  }
+
   // ── Unit save/delete ─────────────────────────────────────────────────────────
   async function saveUnit() {
     formError = null;
@@ -817,6 +855,8 @@
     {/if}
 
     {#if selectedItem?.type === 'unit' || unitFormNew}
+      <!-- svelte-ignore a11y_no_static_element_interactions -->
+      <div onkeydown={onUnitFormKeydown}>
       <h3>{unitFormNew ? 'New Unit' : 'Edit Unit'}</h3>
       <label>
         ID {#if !unitFormNew}<small class="muted">(readonly)</small>{/if}
@@ -871,8 +911,11 @@
           <button class="outline secondary" onclick={deleteUnit}>Delete</button>
         {/if}
       </div>
+      </div><!-- /onkeydown unit form -->
 
     {:else if selectedItem?.type === 'group' || groupFormNew}
+      <!-- svelte-ignore a11y_no_static_element_interactions -->
+      <div onkeydown={onGroupFormKeydown}>
       <h3>{groupFormNew ? 'New Group' : 'Edit Group'}</h3>
       <label>
         ID {#if !groupFormNew}<small class="muted">(readonly)</small>{/if}
@@ -926,6 +969,7 @@
           >Delete</button>
         {/if}
       </div>
+      </div><!-- /onkeydown group form -->
 
     {:else}
       <p class="select-hint">Select a unit or group to edit, or add a new one.</p>