perf(audit-tier-3): bulk-fetch the five hot N+1 loops

Replaces per-row fan-out with grouped queries / inArray pre-fetches
across the five dashboard + cron hotspots flagged in the audit
(MED §13 / HIGH §11–14):

* reminders.processFollowUpReminders — was 3 round trips per
  enabled-and-due interest.  Now: filter in JS, single clients
  bulk-fetch, single reminders bulk-insert, single interests
  bulk-update, one summary socket emit.  1k due interests: 6 round
  trips total instead of 3000+.
* portal.getClientInvoices — was a full-table scan filtered in JS.
  Now an inArray push-down on lower(billingEmail) + defensive
  limit(100).  After 12mo this would have been the worst portal
  endpoint.
* interest-scoring.calculateBulkScores — was 6N round trips
  (1 redis + 1 findFirst + 4 counts per interest).  Now 4 grouped
  count queries on the port's interest set + a single redis pipeline
  to refresh the cache.  1k interests: ~7 round trips.
* document-reminders.processReminderQueue — was 5N round trips per
  cron tick (port + template + lastReminder + pendingSigners + send
  per doc).  Now hoists port + per-type template map + grouped
  lastReminder + bulk pendingSigners; per-row work collapses to a
  Map.get and the documenso send.  500 docs: ~7 round trips.
* inquiry-notifications.sendInquiryNotifications — was sequential
  createNotification + emailQueue.add per recipient inside a public
  POST.  Now Promise.all'd; a 20-user port stops blocking the public
  inquiry POST on ~80 round trips.

Test status: 1168/1168 vitest, tsc clean.

Refs: docs/audit-comprehensive-2026-05-05.md HIGH §§11–14 (auditor-I
Issues 1–4) + MED §13 (auditor-I Issue 5).

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

src/lib/services/reminders.service.ts

@@ -427,27 +427,37 @@ export async function processFollowUpReminders() {
 
     const now = new Date();
 
-    for (const interest of enabledInterests) {
-      if (!interest.reminderDays) continue;
-
-      // Check if enough days have passed since last activity
+    // Pick the interests whose follow-up window has elapsed. Pre-filtering
+    // here means the per-row N+1 walk that used to issue (1 client lookup
+    // + 1 reminder insert + 1 interest update) per interest is replaced by
+    // a single client-bulk-fetch + a single reminder bulk-insert + a
+    // single interests bulk-update against an `inArray` set.
+    const dueInterests = enabledInterests.filter((interest) => {
+      if (!interest.reminderDays) return false;
       const lastActivity = interest.reminderLastFired ?? interest.updatedAt;
       const daysSinceActivity = (now.getTime() - lastActivity.getTime()) / (1000 * 60 * 60 * 24);
+      return daysSinceActivity >= interest.reminderDays;
+    });
 
-      if (daysSinceActivity < interest.reminderDays) continue;
+    if (dueInterests.length === 0) continue;
 
-      // Get client name for the reminder title
-      const client = interest.clientId
-        ? await db.query.clients.findFirst({ where: eq(clients.id, interest.clientId) })
-        : null;
+    const clientIds = Array.from(
+      new Set(dueInterests.map((i) => i.clientId).filter((v): v is string => Boolean(v))),
+    );
+    const clientsByIdEntries =
+      clientIds.length > 0
+        ? await db
+            .select({ id: clients.id, fullName: clients.fullName })
+            .from(clients)
+            .where(inArray(clients.id, clientIds))
+        : [];
+    const clientById = new Map(clientsByIdEntries.map((c) => [c.id, c]));
 
-      const title = client ? `Follow up with ${client.fullName}` : 'Follow up on interest';
-
-      // Find the assigned user (first userPortRole for this port, or fallback)
-      // For now, leave assignedTo null - the notification goes to the port room
-      await db.insert(reminders).values({
+    const newReminders = dueInterests.map((interest) => {
+      const client = interest.clientId ? clientById.get(interest.clientId) : null;
+      return {
         portId: port.id,
-        title,
+        title: client ? `Follow up with ${client.fullName}` : 'Follow up on interest',
         note: 'Auto-generated: no activity detected within the configured follow-up window.',
         dueAt: now,
         priority: 'medium',
@@ -456,23 +466,39 @@ export async function processFollowUpReminders() {
         interestId: interest.id,
         clientId: interest.clientId,
         autoGenerated: true,
-      });
+      };
+    });
 
-      // Update last fired timestamp
+    if (newReminders.length > 0) {
+      await db.insert(reminders).values(newReminders);
       await db
         .update(interests)
         .set({ reminderLastFired: now })
-        .where(eq(interests.id, interest.id));
+        .where(
+          inArray(
+            interests.id,
+            dueInterests.map((i) => i.id),
+          ),
+        );
+    }
 
-      // Fire notification to the port room
+    // Single port-room emit summarising the batch — the per-row emit was
+    // mostly noise to the dashboard and amplified socket traffic linearly
+    // with interest count.
+    if (newReminders.length > 0) {
       emitToRoom(`port:${port.id}`, 'system:alert', {
         alertType: 'follow_up_created',
-        message: title,
+        message: `${newReminders.length} follow-up reminder${
+          newReminders.length === 1 ? '' : 's'
+        } created`,
         severity: 'info',
       });
-
-      logger.info({ interestId: interest.id, portId: port.id }, 'Auto follow-up reminder created');
     }
+
+    logger.info(
+      { portId: port.id, created: newReminders.length },
+      'Auto follow-up reminders created (bulk)',
+    );
   }
 }