feat(finalization): winner email + UI for terminal rounds

When finalizing a round with no further round to advance to, passing teams
are winners — not advancers. Detected for both special-award terminal rounds
(label = award name) and the main competition's terminal round (label =
competition name). Wording uses "a winner" so it works for both single-winner
awards and top-N main-track outcomes.

Adds AWARD_WINNER_NOTIFICATION email type + template ("Your project has won!"
with "our team will reach out about next steps" copy). Routes through the
notification dispatch table the same way ADVANCEMENT_NOTIFICATION does.

The FinalizationSummary gains a `winnerContext` field; the admin finalization
tab uses it to swap "X projects will advance to Y" → "X winners will be
notified for [label]" and renames "Advancement Message" → "Winner Message"
in the custom-message field. The email-preview button shows the winner
template when applicable.

In-app notification (bell icon) gets matching winner copy.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/server/routers/roundEngine.ts

@@ -19,6 +19,7 @@ import {
 } from '../services/round-finalization'
 import {
   getAdvancementNotificationTemplate,
+  getAwardWinnerNotificationTemplate,
   getRejectionNotificationTemplate,
 } from '@/lib/email'
 
@@ -384,30 +385,45 @@ export const roundEngineRouter = router({
           name: true,
           competition: {
             select: {
+              name: true,
               rounds: {
                 select: { id: true, name: true, sortOrder: true, roundType: true },
                 orderBy: { sortOrder: 'asc' },
               },
             },
           },
+          specialAward: { select: { name: true } },
         },
       })
       const rounds = round.competition.rounds
       // Skip MENTORING rounds for display — those are opt-in and not the
       // shared destination for all advancing teams.
-      const toRoundName = findDisplayNextRound(rounds, input.roundId)?.name ?? 'Next Round'
+      const displayNext = findDisplayNextRound(rounds, input.roundId)
 
       const passedCount = await ctx.prisma.projectRoundState.count({
         where: { roundId: input.roundId, proposedOutcome: 'PASSED' },
       })
 
-      const template = getAdvancementNotificationTemplate(
-        'Team Member',
-        'Your Project',
-        round.name,
-        toRoundName,
-        input.customMessage || undefined,
-      )
+      // No further round → passing teams are winners (of the special award if
+      // attached, otherwise of the competition itself).
+      const winnerLabel = !displayNext
+        ? round.specialAward?.name ?? round.competition.name
+        : null
+
+      const template = winnerLabel
+        ? getAwardWinnerNotificationTemplate(
+            'Team Member',
+            'Your Project',
+            winnerLabel,
+            input.customMessage || undefined,
+          )
+        : getAdvancementNotificationTemplate(
+            'Team Member',
+            'Your Project',
+            round.name,
+            displayNext?.name ?? 'Next Round',
+            input.customMessage || undefined,
+          )
 
       return { html: template.html, subject: template.subject, recipientCount: passedCount }
     }),