Update UI and improve archive handling: add reading mode message, adjust button label, and enhance styles for better layout

frontend/index.html

@@ -45,7 +45,7 @@
       </form>
     </dialog>
 
-    <main>
+    <main id="main">
       <section class="capture" aria-labelledby="capture-title">
         <div class="capture-modes" role="tablist" aria-label="Note type">
           <button id="voice-mode" class="capture-mode active" type="button" role="tab" aria-selected="true" aria-controls="voice-panel">Voice</button>
@@ -78,7 +78,7 @@
           <textarea id="written-note" class="written-note" placeholder="What’s on your mind?" rows="7"></textarea>
           <div class="write-actions">
             <span id="draft-status" class="draft-status" role="status">Draft stays on this device until you save it.</span>
-            <button id="save-written-note" class="save-written-note" type="button" disabled>Save note</button>
+            <button id="save-written-note" class="save-written-note" type="button" disabled>Upload note</button>
           </div>
         </div>
       </section>