feat: export Week Ahead as calendar blocks (Closes #1198)

frontend/index.html

@@ -514,6 +514,17 @@
       <div class="small week-review-status" id="week-review-status" role="status" aria-live="polite"></div>
       <button id="confirm-week-plan" type="button">Confirm Week Ahead</button>
     </section>
+    <section class="week-calendar-handoff" id="week-calendar-handoff" aria-labelledby="week-calendar-title" hidden>
+      <div class="small">Calendar handoff</div>
+      <h2 id="week-calendar-title">Add Week Ahead to calendar</h2>
+      <p class="small muted">Choose each day’s start time and exclude anything private. Titles, references, dates, and times are included in a local calendar file; nothing is uploaded.</p>
+      <div class="week-calendar-days" id="week-calendar-days"></div>
+      <div class="small week-calendar-status" id="week-calendar-status" role="status" aria-live="assertive"></div>
+      <div class="week-calendar-actions">
+        <button id="back-to-week-review-from-calendar" type="button">Back to review</button>
+        <button id="share-week-calendar" type="button">Share calendar blocks</button>
+      </div>
+    </section>
     <nav class="mobile-plan-today-nav" aria-label="Plan Today sections">
       <button type="button" data-plan-today-section="fit" aria-current="location">Fit</button>
       <button type="button" data-plan-today-section="today">Today</button>
@@ -2016,6 +2027,7 @@
 <script src="static/plan-today-readiness.js"></script>
 <script src="static/plan-today-preview.js"></script>
 <script src="static/tomorrow-plan.js"></script>
+<script src="static/week-calendar.js"></script>
 <script src="static/week-plan.js"></script>
 <script src="static/search-week-plan.js"></script>
 <script src="static/today-sync.js"></script>