refactor(services): centralize AuditMeta + transactional setEntityTags helper

The same `interface AuditMeta { userId; portId; ipAddress; userAgent }`
was duplicated in 26 service files. Move the canonical definition into
`@/lib/audit` next to the related types and update every service to
import it. `ServiceAuditMeta` (the alias used in invoices.ts and
expenses.ts) collapses into the same name.

Tag CRUD across clients/companies/yachts/interests/berths followed an
identical wipe-then-rewrite recipe with two latent issues: the delete
and insert weren't wrapped in a transaction (a partial failure left
the entity with zero tags) and the audit-log payload shape diverged
(`newValue: { tagIds }` for clients/yachts/companies but
`metadata: { type: 'tags_updated', tagIds }` for interests/berths).

Extract `setEntityTags` in `entity-tags.helper.ts` that performs the
delete+insert inside a single transaction, normalizes the audit payload
to `newValue: { tagIds }`, and dispatches the per-entity socket event
through a switch so `ServerToClientEvents` typing stays intact.

The five `setXTags(...)` service functions now do parent-row tenant
verification and delegate the join-table work + side effects.

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

src/lib/services/settings.service.ts

@@ -2,17 +2,10 @@ import { and, eq, isNull } from 'drizzle-orm';
 
 import { db } from '@/lib/db';
 import { systemSettings } from '@/lib/db/schema';
-import { createAuditLog } from '@/lib/audit';
+import { createAuditLog, type AuditMeta } from '@/lib/audit';
 import { NotFoundError } from '@/lib/errors';
 import { emitToRoom } from '@/lib/socket/server';
 
-interface AuditMeta {
-  userId: string;
-  portId: string;
-  ipAddress: string;
-  userAgent: string;
-}
-
 export async function listSettings(portId: string) {
   // Get port-specific settings
   const portSettings = await db