Member updates: saved draft (loads into the admin card, Save draft button)

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

public/admin.html

@@ -402,7 +402,7 @@
               <label class="small">Subject<input id="updSubject" type="text" maxlength="150" placeholder="What is new on InstantAdPay this week"></label>
               <label class="small">Intro (optional, plain text)<textarea id="updIntro" rows="4" style="width:100%" placeholder="Quick one. Three things shipped since my last note, and the third one is the one to try today."></textarea></label>
               <label class="small">Audience<select id="updAudience"></select></label>
-              <div style="display:flex;gap:8px;flex-wrap:wrap"><button type="button" class="btn small sec" id="updPreview">Preview</button><button type="button" class="btn small sec" id="updTest">Send test to me</button><button type="button" class="btn small" id="updSend">Send</button></div>
+              <div style="display:flex;gap:8px;flex-wrap:wrap"><button type="button" class="btn small sec" id="updSaveDraft">Save draft</button><button type="button" class="btn small sec" id="updPreview">Preview</button><button type="button" class="btn small sec" id="updTest">Send test to me</button><button type="button" class="btn small" id="updSend">Send</button></div>
               <pre id="updPre" class="small" hidden style="white-space:pre-wrap;background:rgba(255,255,255,.04);border:1px solid var(--line);border-radius:10px;padding:10px;max-height:320px;overflow:auto"></pre>
             </div>
             <div>
@@ -480,6 +480,6 @@
 </div>
 
 <script src="/assets/common.js?v=20260914a"></script>
-<script src="/assets/admin.js?v=20260914b"></script>
+<script src="/assets/admin.js?v=20260914c"></script>
 </body>
 </html>