feat(documents): syncEntityFolderName + entity-rename hooks

Per-entity subfolder names mirror the entity's current display string.
Wired into updateClient / updateCompany / updateYacht; runs only when
the name field changes. Best-effort (logged + swallowed) so a folder-
sync error never fails an entity update. Preserves the (archived)
suffix when present; skips entirely when the folder has been demoted
to (deleted) — the rep owns the name at that point.

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

src/lib/services/document-folders.service.ts

@@ -515,3 +515,59 @@ export async function ensureEntityFolder(
   }
   throw new ConflictError(`Could not allocate a unique folder name for ${baseName}`);
 }
+
+/**
+ * Rename the per-entity subfolder to match the entity's current display
+ * name. Called from the entity rename services (`updateClient`,
+ * `updateCompany`, `updateYacht`). No-op when the folder does not exist
+ * (lazy creation — entities without a folder skip the sync entirely).
+ *
+ * Sibling-name collision is resolved by suffix bump (matches
+ * `ensureEntityFolder` semantics).
+ *
+ * Intentionally does NOT call `assertNotSystemManaged` — this helper
+ * is the legitimate path for renaming a system folder.
+ */
+export async function syncEntityFolderName(
+  portId: string,
+  entityType: EntityType,
+  entityId: string,
+  _userId: string,
+): Promise<void> {
+  if (!ENTITY_TYPES.has(entityType)) return;
+
+  const folder = await db.query.documentFolders.findFirst({
+    where: and(
+      eq(documentFolders.portId, portId),
+      eq(documentFolders.entityType, entityType),
+      eq(documentFolders.entityId, entityId),
+    ),
+  });
+  if (!folder) return; // Lazy creation — nothing to sync yet.
+
+  // Preserve archived suffix if present.
+  const isArchived = folder.name.endsWith(' (archived)');
+  const isDeleted = folder.name.endsWith(' (deleted)');
+  if (isDeleted) return; // Demoted; rep owns the name now.
+
+  const baseName = await resolveEntityDisplayName(portId, entityType, entityId);
+  const targetSuffix = isArchived ? ' (archived)' : '';
+
+  for (let attempt = 0; attempt < 50; attempt += 1) {
+    const candidate =
+      attempt === 0 ? `${baseName}${targetSuffix}` : `${baseName} (${attempt + 1})${targetSuffix}`;
+    if (candidate === folder.name) return; // No-op rename.
+    try {
+      const [updated] = await db
+        .update(documentFolders)
+        .set({ name: candidate, updatedAt: new Date() })
+        .where(eq(documentFolders.id, folder.id))
+        .returning();
+      if (updated) return;
+    } catch (err) {
+      if (isSiblingNameConflict(err)) continue;
+      throw err;
+    }
+  }
+  throw new ConflictError(`Could not allocate a unique folder name for ${baseName}`);
+}