feat: add email preview to award notification and finalization tab

- Award "Notify Pool" dialog now uses EmailPreviewDialog with live preview
- Button shows eligible project count: "Notify Pool (38)"
- Finalization tab email section has "Preview" buttons for both
  advancement and rejection messages
- EmailPreviewDialog supports previewOnly mode (close button, no send)
- Backend: previewAwardSelectionEmail, previewFinalizationAdvancementEmail,
  previewFinalizationRejectionEmail queries

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/components/admin/round/finalization-tab.tsx

@@ -39,9 +39,11 @@ import {
   ChevronRight,
   Mail,
   Send,
+  Eye,
 } from 'lucide-react'
 import { cn } from '@/lib/utils'
 import { projectStateConfig } from '@/lib/round-config'
+import { EmailPreviewDialog } from './email-preview-dialog'
 
 // ── Types ──────────────────────────────────────────────────────────────────
 
@@ -81,6 +83,10 @@ export function FinalizationTab({ roundId, roundStatus }: FinalizationTabProps)
   const [emailSectionOpen, setEmailSectionOpen] = useState(false)
   const [advancementMessage, setAdvancementMessage] = useState('')
   const [rejectionMessage, setRejectionMessage] = useState('')
+  const [advancePreviewOpen, setAdvancePreviewOpen] = useState(false)
+  const [rejectPreviewOpen, setRejectPreviewOpen] = useState(false)
+  const [advancePreviewMsg, setAdvancePreviewMsg] = useState<string | undefined>()
+  const [rejectPreviewMsg, setRejectPreviewMsg] = useState<string | undefined>()
 
   // Mutations
   const updateOutcome = trpc.roundEngine.updateProposedOutcome.useMutation({
@@ -121,6 +127,16 @@ export function FinalizationTab({ roundId, roundStatus }: FinalizationTabProps)
     onError: (err) => toast.error(err.message),
   })
 
+  // Email preview queries
+  const advancePreview = trpc.roundEngine.previewFinalizationAdvancementEmail.useQuery(
+    { roundId, customMessage: advancePreviewMsg },
+    { enabled: advancePreviewOpen }
+  )
+  const rejectPreview = trpc.roundEngine.previewFinalizationRejectionEmail.useQuery(
+    { roundId, customMessage: rejectPreviewMsg },
+    { enabled: rejectPreviewOpen }
+  )
+
   // Filtered projects
   const filteredProjects = useMemo(() => {
     if (!summary) return []
@@ -624,7 +640,21 @@ export function FinalizationTab({ roundId, roundStatus }: FinalizationTabProps)
                 </div>
               )}
               <div>
-                <label className="text-sm font-medium mb-1.5 block">Advancement Message</label>
+                <div className="flex items-center justify-between mb-1.5">
+                  <label className="text-sm font-medium">Advancement Message</label>
+                  <Button
+                    variant="ghost"
+                    size="sm"
+                    className="h-7 text-xs"
+                    onClick={() => {
+                      setAdvancePreviewMsg(advancementMessage || undefined)
+                      setAdvancePreviewOpen(true)
+                    }}
+                  >
+                    <Eye className="h-3.5 w-3.5 mr-1" />
+                    Preview
+                  </Button>
+                </div>
                 <Textarea
                   placeholder="Custom message for projects that are advancing (added to the standard email template)..."
                   value={advancementMessage}
@@ -633,7 +663,21 @@ export function FinalizationTab({ roundId, roundStatus }: FinalizationTabProps)
                 />
               </div>
               <div>
-                <label className="text-sm font-medium mb-1.5 block">Rejection Message</label>
+                <div className="flex items-center justify-between mb-1.5">
+                  <label className="text-sm font-medium">Rejection Message</label>
+                  <Button
+                    variant="ghost"
+                    size="sm"
+                    className="h-7 text-xs"
+                    onClick={() => {
+                      setRejectPreviewMsg(rejectionMessage || undefined)
+                      setRejectPreviewOpen(true)
+                    }}
+                  >
+                    <Eye className="h-3.5 w-3.5 mr-1" />
+                    Preview
+                  </Button>
+                </div>
                 <Textarea
                   placeholder="Custom message for projects that are not advancing (added to the standard email template)..."
                   value={rejectionMessage}
@@ -718,6 +762,34 @@ export function FinalizationTab({ roundId, roundStatus }: FinalizationTabProps)
           </CardContent>
         </Card>
       )}
+
+      {/* Email Preview Dialogs */}
+      <EmailPreviewDialog
+        open={advancePreviewOpen}
+        onOpenChange={setAdvancePreviewOpen}
+        title="Advancement Email Preview"
+        description="Preview of the email sent to advancing project teams"
+        recipientCount={advancePreview.data?.recipientCount ?? passedCount}
+        previewHtml={advancePreview.data?.html}
+        isPreviewLoading={advancePreview.isLoading}
+        onSend={() => setAdvancePreviewOpen(false)}
+        isSending={false}
+        showCustomMessage={false}
+        previewOnly
+      />
+      <EmailPreviewDialog
+        open={rejectPreviewOpen}
+        onOpenChange={setRejectPreviewOpen}
+        title="Rejection Email Preview"
+        description="Preview of the email sent to non-advancing project teams"
+        recipientCount={rejectPreview.data?.recipientCount ?? rejectedCount}
+        previewHtml={rejectPreview.data?.html}
+        isPreviewLoading={rejectPreview.isLoading}
+        onSend={() => setRejectPreviewOpen(false)}
+        isSending={false}
+        showCustomMessage={false}
+        previewOnly
+      />
     </div>
   )
 }