feat(hq-web): reminder email preview in the manual queue

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

apps/hq-web/src/pages/Dashboard.tsx

@@ -2,7 +2,7 @@ import { useState, type ReactNode } from 'react'
 import { useNavigate } from 'react-router-dom'
 import { formatINR } from '@sims/domain'
 import { Badge, Button, DataTable, EmptyState, Notice, PageHeader, StatCard, Stats } from '@sims/ui'
-import { getDashboard, sendReminder, dismissReminder, type Reminder } from '../api'
+import { getDashboard, sendReminder, dismissReminder, getReminderPreview, type Reminder } from '../api'
 import { useData } from './Clients'
 
 const inr = (p: number) => formatINR(p)
@@ -105,20 +105,43 @@ function Section<T>(props: {
 
 function QueueActions(props: { rem: Reminder & { docNo: string | null }; onDone: () => void; onError: (m: string) => void }) {
   const [busy, setBusy] = useState(false)
+  const [mail, setMail] = useState<{ subject: string; body: string } | undefined>()
+  const [loading, setLoading] = useState(false)
   const run = (p: Promise<unknown>) => {
     setBusy(true); props.onError('')
     p.catch((e: Error) => props.onError(e.message))
       // Reload even on failure: the server has already parked the reminder as
-      // 'failed' with its error, and the row must flip live (Task 12 walk §3.2).
+      // 'failed' with its error, and the row must flip live.
       .then(props.onDone)
       .finally(() => setBusy(false))
   }
+  const preview = () => {
+    if (mail !== undefined) { setMail(undefined); return } // toggle closed
+    setLoading(true); props.onError('')
+    getReminderPreview(props.rem.id)
+      .then(setMail)
+      .catch((e: Error) => props.onError(e.message))
+      .finally(() => setLoading(false))
+  }
   return (
+    <div style={{ display: 'flex', flexDirection: 'column', gap: 6 }}>
       <div style={{ display: 'flex', gap: 6 }}>
         {SENDABLE.has(props.rem.ruleKind) && (
+          <>
+            <Button onClick={preview}>{loading ? '…' : mail !== undefined ? 'Hide' : 'Preview'}</Button>
             <Button tone="primary" onClick={() => run(sendReminder(props.rem.id))}>{busy ? '…' : 'Send'}</Button>
+          </>
         )}
         <Button onClick={() => run(dismissReminder(props.rem.id))}>Dismiss</Button>
       </div>
+      {mail !== undefined && (
+        <div style={{ border: '1px solid var(--border)', borderRadius: 6, padding: '6px 8px', background: 'var(--bg-raised)', maxWidth: 420 }}>
+          <div style={{ fontSize: 11, textTransform: 'uppercase', color: 'var(--text-muted, #666)' }}>Subject</div>
+          <div style={{ fontWeight: 600, marginBottom: 4 }}>{mail.subject}</div>
+          <div style={{ fontSize: 11, textTransform: 'uppercase', color: 'var(--text-muted, #666)' }}>Body</div>
+          <pre style={{ whiteSpace: 'pre-wrap', margin: 0, fontFamily: 'inherit', fontSize: 13 }}>{mail.body}</pre>
+        </div>
+      )}
+    </div>
   )
 }