Add layout visibility toggles and improve search bar UI

Introduces checkboxes in the edit toolbar to toggle visibility of the greeting, bookmarks, and 'At A Glance' widgets, persisting user preferences in localStorage. Refactors the search bar and search engine selector for a unified, glassy pill appearance and improved responsiveness. The clock now displays hours and minutes only, updating precisely at the start of each minute. Draggable elements are clamped to remain within the viewport, and visibility changes are applied immediately and on save/cancel.

renderer/home.html

@@ -62,11 +62,11 @@
   <!-- At a glance widget -->
   <aside class="glance" aria-live="polite">
     <div class="glance-card">
-      <div class="glance-title">At a glance</div>
+      <div class="glance-title">At A Glance</div>
       <div class="glance-grid">
         <div class="glance-tile">
           <div class="glance-label">Time</div>
-          <div id="clock" class="glance-value">--:--:--</div>
+          <div id="clock" class="glance-value">--:--</div>
         </div>
         <div class="glance-tile">
           <div class="glance-label">Weather</div>
@@ -78,6 +78,18 @@
 
   <!-- Edit mode toolbar -->
   <div id="editToolbar" class="edit-toolbar" hidden>
+    <label style="display:flex;align-items:center;gap:6px;margin-right:8px;">
+      <input type="checkbox" id="toggleShowGreeting" checked>
+      <span>Show greeting</span>
+    </label>
+    <label style="display:flex;align-items:center;gap:6px;margin-right:8px;">
+      <input type="checkbox" id="toggleShowBookmarks" checked>
+      <span>Show bookmarks</span>
+    </label>
+    <label style="display:flex;align-items:center;gap:6px;margin-right:12px;">
+      <input type="checkbox" id="toggleShowGlance" checked>
+      <span>Show At a Glance</span>
+    </label>
     <button id="cancelEditBtn" class="btn secondary" aria-label="Cancel layout edits">Cancel</button>
     <button id="saveEditBtn" class="btn primary" aria-label="Save layout edits">Save</button>
   </div>