Award shortlist UX improvements + configurable invite link expiry

Award shortlist:
- Expandable reasoning text (click to toggle, hover hint)
- Bulk select/deselect all checkbox in header
- Top N projects highlighted with amber background
- New bulkToggleShortlisted backend mutation

Invite link expiry:
- New "Invitation Link Expiry (hours)" field in Security Settings
- Reads from systemSettings `invite_link_expiry_hours` (default 72h / 3 days)
- Email template dynamically shows "X hours" or "X days" based on setting
- All 3 invite paths (bulk create, single invite, bulk resend) use setting

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

src/server/routers/specialAward.ts

@@ -972,6 +972,28 @@ export const specialAwardRouter = router({
       return { shortlisted: updated.shortlisted }
     }),
 
+  /**
+   * Bulk toggle shortlisted status for multiple projects
+   */
+  bulkToggleShortlisted: adminProcedure
+    .input(z.object({
+      awardId: z.string(),
+      projectIds: z.array(z.string()),
+      shortlisted: z.boolean(),
+    }))
+    .mutation(async ({ ctx, input }) => {
+      const result = await ctx.prisma.awardEligibility.updateMany({
+        where: {
+          awardId: input.awardId,
+          projectId: { in: input.projectIds },
+          eligible: true,
+        },
+        data: { shortlisted: input.shortlisted },
+      })
+
+      return { updated: result.count, shortlisted: input.shortlisted }
+    }),
+
   /**
    * Confirm shortlist — for SEPARATE_POOL awards, creates ProjectRoundState entries
    */