feat: plan Week Ahead in one mobile pass (Closes #1186)

frontend/index.html

@@ -460,6 +460,7 @@
       <div><h2 id="plan-today-title">Plan Today</h2><p class="small muted">Choose and order the work you want to finish next.</p></div>
       <button id="cancel-plan-today" type="button">Cancel</button>
     </div>
+    <p class="week-plan-progress" id="week-plan-progress" aria-live="polite" hidden></p>
     <nav class="week-plan-dates" id="week-plan-dates" aria-label="Week Ahead dates" hidden></nav>
     <section class="tomorrow-conflict-review" id="tomorrow-conflict-review" aria-labelledby="tomorrow-conflict-title" hidden>
       <div class="small">Cross-device change</div>