feat(uat-batch-13): activity feed resolves user UUIDs to display names

Audit-log rows with user-FK diffs (assignedTo, ownerId, reassignedTo,
createdBy, addedBy, changedBy, transferredBy) previously rendered the
raw user UUID in the activity feed (e.g. "→ mEcsLxo5kyFMyhbOSehxJjY…").
Same gap on the row's actor — the rep had no idea who did what.

- getRecentActivity collects all userIds referenced by either the row's
  actor (auditLogs.userId) or by user-FK diff values, then bulk-fetches
  user_profiles in a single query. Output rows now carry an
  `actorName` field and have their `oldValue`/`newValue` swapped for
  display names on user-FK fields.
- Unknown / deleted users fall back to "Unknown user (#short-uuid)" so
  the audit trail stays useful for forensics.
- ActivityItem client type extended with `actorName`. Existing
  consumers still read the raw `userId` for forensics + deep-link.

tsc clean. 1419/1419 vitest pass.

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

src/lib/services/dashboard.service.ts

@@ -11,6 +11,7 @@ import { documents } from '@/lib/db/schema/documents';
 import { reminders } from '@/lib/db/schema/operations';
 import { ports } from '@/lib/db/schema/ports';
 import { systemSettings, auditLogs } from '@/lib/db/schema/system';
+import { userProfiles } from '@/lib/db/schema/users';
 import { PIPELINE_STAGES, STAGE_WEIGHTS } from '@/lib/constants';
 import { activeInterestsWhere } from '@/lib/services/active-interest';
 import { convert as convertCurrency } from '@/lib/services/currency';
@@ -454,8 +455,61 @@ export async function getRecentActivity(portId: string, limit = 20) {
     ),
   ]);
 
-  return rows.map((r) => ({
-    ...r,
-    label: r.entityId ? (labels.get(`${r.entityType}:${r.entityId}`) ?? null) : null,
-  }));
+  // Resolve user UUIDs that appear as the actor (auditLogs.userId) and
+  // as oldValue/newValue on user-FK diff rows (assignedTo, ownerId,
+  // reassignedTo, createdBy). Activity-feed audit-log rows previously
+  // rendered the raw UUID prefix, which was unreadable.
+  const USER_FK_FIELDS = new Set([
+    'assignedTo',
+    'ownerId',
+    'reassignedTo',
+    'createdBy',
+    'addedBy',
+    'changedBy',
+    'transferredBy',
+  ]);
+  const userIds = new Set<string>();
+  for (const r of rows) {
+    if (r.userId) userIds.add(r.userId);
+    if (r.fieldChanged && USER_FK_FIELDS.has(r.fieldChanged)) {
+      if (typeof r.oldValue === 'string') userIds.add(r.oldValue);
+      if (typeof r.newValue === 'string') userIds.add(r.newValue);
+    }
+  }
+  const userNames = new Map<string, string>();
+  if (userIds.size > 0) {
+    const profiles = await db
+      .select({
+        userId: userProfiles.userId,
+        displayName: userProfiles.displayName,
+        firstName: userProfiles.firstName,
+        lastName: userProfiles.lastName,
+      })
+      .from(userProfiles)
+      .where(inArray(userProfiles.userId, Array.from(userIds)));
+    for (const p of profiles) {
+      const name = [p.firstName, p.lastName].filter(Boolean).join(' ').trim() || p.displayName;
+      userNames.set(p.userId, name);
+    }
+  }
+  function resolveUser(id: unknown): unknown {
+    if (typeof id !== 'string') return id;
+    const name = userNames.get(id);
+    if (name) return name;
+    return `Unknown user (#${id.slice(0, 8)})`;
+  }
+
+  return rows.map((r) => {
+    const isUserFk = r.fieldChanged && USER_FK_FIELDS.has(r.fieldChanged);
+    return {
+      ...r,
+      label: r.entityId ? (labels.get(`${r.entityType}:${r.entityId}`) ?? null) : null,
+      // Replace user UUIDs with display names; non-user-FK rows pass through.
+      oldValue: isUserFk ? resolveUser(r.oldValue) : r.oldValue,
+      newValue: isUserFk ? resolveUser(r.newValue) : r.newValue,
+      // Surfaces the actor's name to the renderer; original userId stays
+      // available for forensics / deep-link if a later UI needs it.
+      actorName: r.userId ? (userNames.get(r.userId) ?? null) : null,
+    };
+  });
 }