DC-085 link-first invite — Discord-style share it however you want

Flip POST /api/v1/auth/admin/invites default to no email; always return
the link. Operators copy + share via iMessage/WhatsApp/SMS/Signal/Telegram/
Discord/paste-in-email. Email becomes an opt-in checkbox (was the default).
Add shareText field with pre-formatted message for one-tap paste. Stop
logging raw invite URLs to error.log when SMTP is unconfigured (was just
a dev fallback — link is now in the response). Frontend flips the
checkbox default to unchecked and renders shareText + native share sheet
button (navigator.share) alongside the raw copy-link button. 9 new tests
covering default-no-send, link-always-returned, shareText-shape, opt-in
SMTP send, failed-SMTP-no-leak. Full suite: 2474/2474 + 9 new = 2483.

status/js/admin.js

@@ -216,8 +216,8 @@
       _el('input', { name: 'ttlHours', type: 'number', min: '1', max: '168', value: '24', style: 'padding:6px;width:80px' }),
     ));
     form.appendChild(_el('label', { style: 'display:flex;gap:4px;align-items:center;font-size:0.85rem' },
-      _el('input', { name: 'sendEmail', type: 'checkbox', checked: true }),
-      _el('span', { text: 'Send email' }),
+      _el('input', { name: 'sendEmail', type: 'checkbox', checked: false }),
+      _el('span', { text: 'Also send via email (optional)' }),
     ));
     form.appendChild(_el('button', { type: 'submit', class: 'btn-sm', style: 'padding:6px 12px', text: 'Issue invite' }));
     container.appendChild(form);
@@ -297,16 +297,77 @@
       },
     });
     banner.appendChild(copyBtn);
-    if (invite.deliveredVia === 'dev-console') {
+
+    // DC-085: pre-formatted message for one-tap paste into iMessage / WhatsApp /
+    // Telegram / SMS / Signal / Discord / paste-into-email. The operator can
+    // copy this as a sentence instead of dealing with the raw URL.
+    if (invite.shareText) {
+      const shareBlock = _el('div', { style: 'margin-top:12px' });
+      shareBlock.appendChild(_el('div', {
+        style: 'font-size:0.8rem;color:#86efac;margin-bottom:4px',
+        text: 'Share this message:',
+      }));
+      shareBlock.appendChild(_el('div', {
+        style: 'padding:8px;background:#000;border-radius:4px;color:#d1fae5;white-space:pre-wrap',
+        text: invite.shareText,
+      }));
+      const shareActions = _el('div', { style: 'margin-top:6px;display:flex;gap:6px;flex-wrap:wrap' });
+      const copyTextBtn = _el('button', {
+        class: 'btn-sm', style: 'padding:4px 10px',
+        text: 'Copy message',
+        onclick: async () => {
+          try {
+            await navigator.clipboard.writeText(invite.shareText);
+            copyTextBtn.textContent = 'Copied!';
+            setTimeout(() => { copyTextBtn.textContent = 'Copy message'; }, 2000);
+          } catch (e) {
+            window.errorHandler && window.errorHandler.show('Clipboard blocked: select the text manually.');
+          }
+        },
+      });
+      shareActions.appendChild(copyTextBtn);
+      // Native share sheet on mobile / supported browsers. Falls back silently
+      // (the copy buttons cover the same intent).
+      if (typeof navigator !== 'undefined' && typeof navigator.share === 'function') {
+        const nativeShareBtn = _el('button', {
+          class: 'btn-sm', style: 'padding:4px 10px',
+          text: 'Share via…',
+          onclick: async () => {
+            try {
+              await navigator.share({
+                title: 'DashCaddy invite',
+                text: invite.shareText,
+                url: invite.acceptUrl,
+              });
+            } catch (e) {
+              // User-cancelled throws AbortError — that's fine, just stay quiet.
+              if (e && e.name && e.name !== 'AbortError') {
+                window.errorHandler && window.errorHandler.show('Share failed: ' + e.message);
+              }
+            }
+          },
+        });
+        shareActions.appendChild(nativeShareBtn);
+      }
+      shareBlock.appendChild(shareActions);
+      banner.appendChild(shareBlock);
+    }
+
+    if (invite.deliveredVia === 'failed') {
       banner.appendChild(_el('p', {
         style: 'margin-top:8px;color:#fbbf24;font-size:0.8rem',
-        text: 'SMTP not configured — the invite was logged to the server console (search for [DC-048-DEV-INVITE-LINK]).',
+        text: 'Email could not be sent (SMTP not configured). Share the link above instead — it works the same way.',
       }));
     } else if (invite.deliveredVia === 'email') {
       banner.appendChild(_el('p', {
         style: 'margin-top:8px;color:#86efac;font-size:0.8rem',
         text: 'Email sent to ' + invite.email + '.',
       }));
+    } else if (invite.deliveredVia === 'manual') {
+      banner.appendChild(_el('p', {
+        style: 'margin-top:8px;color:#86efac;font-size:0.8rem',
+        text: 'Share the link above via text, chat, or any messenger.',
+      }));
     }
     parent.appendChild(banner);
   }