Add Compare with Resend panel to Subscribers; stop resubscribing opted-out contacts; v2.6.1

- Subscribers: compare in-app list with Resend audience/segment, with one-click fixes
- syncContactToResend no longer resets unsubscribed on existing contacts

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

src/AdminPage.tsx

@@ -662,6 +662,19 @@ interface Subscriber {
 }
 
 
+interface ResendComparison {
+  appCount: number
+  resendCount: number
+  resendUnsubscribedCount: number
+  segmentConfigured: boolean
+  segmentCount: number | null
+  matched: number
+  onlyInApp: Array<{ name: string; email: string }>
+  onlyInResend: Array<{ name: string; email: string }>
+  unsubscribedInResend: Array<{ name: string; email: string }>
+  notInSegment: Array<{ name: string; email: string }>
+}
+
 type StringField = Exclude<keyof SiteContent, 'customLinks' | 'customBlocks' | 'redirects' | 'podcastFeaturedLinks' | 'finishedBooks' | 'testimonials' | 'seo' | 'legal' | 'whereToNextCards' | 'colossiansStudySections' | 'studies'>
 
 type AdminView =
@@ -1583,6 +1596,10 @@ export default function AdminPage({ content, onSave, onLogout }: Props) {
   const [mobileNavOpen, setMobileNavOpen] = useState(false)
   const [navSearch, setNavSearch] = useState('')
   const [subscribers, setSubscribers] = useState<Subscriber[]>([])
+  const [resendCmp, setResendCmp] = useState<ResendComparison | null>(null)
+  const [resendCmpLoading, setResendCmpLoading] = useState(false)
+  const [resendCmpBusy, setResendCmpBusy] = useState(false)
+  const [resendCmpMsg, setResendCmpMsg] = useState('')
   const [subscriberSearch, setSubscriberSearch] = useState('')
   const [downloadStats, setDownloadStats] = useState<Record<string, number>>({})
   // Study comments moderation state
@@ -3495,12 +3512,92 @@ const [dashboardNow, setDashboardNow] = useState(() => new Date())
               s.name.toLowerCase().includes(subscriberSearch.toLowerCase()) ||
               s.email.toLowerCase().includes(subscriberSearch.toLowerCase())
             )
+            async function runResendCompare() {
+              setResendCmpLoading(true); setResendCmpMsg('')
+              try {
+                const r = await fetch('/api/admin-subscribers/resend-compare')
+                const d = await r.json()
+                if (!r.ok) setResendCmpMsg(d.message || 'Comparison failed.')
+                else setResendCmp(d as ResendComparison)
+              } catch { setResendCmpMsg('Network error. Try again.') }
+              finally { setResendCmpLoading(false) }
+            }
+            async function runResendSync(action: 'add-to-resend' | 'add-to-segment' | 'apply-unsubscribes', prompt: string) {
+              if (!confirm(prompt)) return
+              setResendCmpBusy(true); setResendCmpMsg('')
+              try {
+                const r = await fetch('/api/admin-subscribers/resend-sync', {
+                  method: 'POST',
+                  headers: { 'Content-Type': 'application/json' },
+                  body: JSON.stringify({ action }),
+                })
+                const d = await r.json()
+                if (!r.ok) { setResendCmpMsg(d.message || 'Sync failed.'); return }
+                setResendCmpMsg(`Done: ${d.done} updated${d.failed ? `, ${d.failed} failed` : ''}${d.remaining ? `, ${d.remaining} more — run the action again` : ''}.`)
+                const subsRes = await fetch('/api/admin-subscribers')
+                if (subsRes.ok) setSubscribers(((await subsRes.json()) as { subscribers: Subscriber[] }).subscribers ?? [])
+                await runResendCompare()
+              } catch { setResendCmpMsg('Network error. Try again.') }
+              finally { setResendCmpBusy(false) }
+            }
+            const renderCmpList = (title: string, note: string, rows: Array<{ name: string; email: string }>, action?: React.ReactNode) => (
+              <details className="cmp-group" open={rows.length > 0 && rows.length <= 10}>
+                <summary>
+                  <span className={`cmp-count${rows.length === 0 ? ' is-zero' : ''}`}>{rows.length}</span>
+                  <span className="cmp-title">{title}</span>
+                </summary>
+                <p className="cmp-note">{note}</p>
+                {rows.length > 0 && (
+                  <ul className="cmp-rows">
+                    {rows.slice(0, 200).map(r => <li key={r.email}><span>{r.name || '—'}</span><a href={`mailto:${r.email}`}>{r.email}</a></li>)}
+                    {rows.length > 200 && <li className="cmp-more">…and {rows.length - 200} more</li>}
+                  </ul>
+                )}
+                {rows.length > 0 && action}
+              </details>
+            )
             return (
               <section className="admin-panel-section">
                 <div className="admin-panel-head">
                   <h2>Subscribers</h2>
                   <p>{subscribers.length} people have opted in to email updates.</p>
                 </div>
+
+                <div className="cmp-card">
+                  <div className="cmp-head">
+                    <div>
+                      <strong>Compare with Resend</strong>
+                      <p className="cmp-note" style={{ margin: '0.2rem 0 0' }}>Checks that everyone who opted in here is also in your Resend audience, and that nobody who unsubscribed there is still active here.</p>
+                    </div>
+                    <button type="button" className="btn-admin-reset" disabled={resendCmpLoading || resendCmpBusy} onClick={() => void runResendCompare()}>
+                      {resendCmpLoading ? 'Checking Resend…' : resendCmp ? 'Re-check' : 'Run comparison'}
+                    </button>
+                  </div>
+                  {resendCmpMsg && <p className="admin-stats-note" role="status">{resendCmpMsg}</p>}
+                  {resendCmp && (() => {
+                    const c = resendCmp
+                    const inSync = c.onlyInApp.length === 0 && c.unsubscribedInResend.length === 0 && c.notInSegment.length === 0
+                    return (
+                      <>
+                        <div className="cmp-stats">
+                          <div><b>{c.appCount}</b><span>Subscribers here</span></div>
+                          <div><b>{c.resendCount}</b><span>Contacts in Resend{c.resendUnsubscribedCount ? ` (${c.resendUnsubscribedCount} unsubscribed)` : ''}</span></div>
+                          {c.segmentCount !== null && <div><b>{c.segmentCount}</b><span>In your Resend segment</span></div>}
+                          <div><b>{c.matched}</b><span>Fully matched</span></div>
+                        </div>
+                        {inSync && <p className="cmp-ok">✓ Every subscriber here is in Resend and active. {c.onlyInResend.length > 0 ? `Resend also has ${c.onlyInResend.length} other active contact${c.onlyInResend.length === 1 ? '' : 's'} (see below).` : ''}</p>}
+                        {!c.segmentConfigured && <p className="cmp-note">Note: RESEND_SEGMENT_ID isn’t set on the server, so segment membership wasn’t checked and new contacts aren’t added to a segment.</p>}
+                        {renderCmpList('Subscribed here, missing from Resend', 'These people opted in on the site but never made it into Resend, so Resend broadcasts won’t reach them.', c.onlyInApp,
+                          <button type="button" className="btn-admin-apply" disabled={resendCmpBusy} onClick={() => void runResendSync('add-to-resend', `Add ${c.onlyInApp.length} subscriber${c.onlyInApp.length === 1 ? '' : 's'} to Resend? (Up to 100 at a time.)`)}>{resendCmpBusy ? 'Working…' : `Add ${Math.min(c.onlyInApp.length, 100)} to Resend`}</button>)}
+                        {renderCmpList('Unsubscribed in Resend, still active here', 'They opted out through Resend. Marking them unsubscribed here stops the in-app Broadcast Email from sending to them.', c.unsubscribedInResend,
+                          <button type="button" className="btn-admin-apply" disabled={resendCmpBusy} onClick={() => void runResendSync('apply-unsubscribes', `Mark ${c.unsubscribedInResend.length} person${c.unsubscribedInResend.length === 1 ? '' : 's'} as unsubscribed here? They will be removed from the subscriber list and future broadcasts.`)}>{resendCmpBusy ? 'Working…' : 'Mark unsubscribed here'}</button>)}
+                        {c.segmentConfigured && renderCmpList('In Resend, but not in your segment', 'These subscribers exist in Resend but aren’t in the segment your broadcasts use.', c.notInSegment,
+                          <button type="button" className="btn-admin-apply" disabled={resendCmpBusy} onClick={() => void runResendSync('add-to-segment', `Add ${c.notInSegment.length} contact${c.notInSegment.length === 1 ? '' : 's'} to the Resend segment? (Up to 100 at a time.)`)}>{resendCmpBusy ? 'Working…' : `Add ${Math.min(c.notInSegment.length, 100)} to segment`}</button>)}
+                        {renderCmpList('In Resend, not subscribed here', 'Informational only. These are usually study-account signups, or people who opted in before the site tracked it. Nothing is changed for them.', c.onlyInResend)}
+                      </>
+                    )
+                  })()}
+                </div>
                 <div className="admin-toolbar" style={{ marginBottom: '1rem', display: 'flex', gap: '0.75rem', alignItems: 'center', flexWrap: 'wrap' }}>
                   <input
                     type="search"