feat(activity): per-entity Activity timeline (clients/yachts/companies/berths)

Until now only the global /admin/audit page surfaced audit_logs. Each
entity detail page either lacked the Activity tab entirely or rendered
"Activity log coming soon" text.

- entity-activity.service.loadEntityActivity wraps searchAuditLogs
  with actor-email resolution; reused by all 5 endpoints.
- New endpoints: /api/v1/{clients,yachts,companies,berths,interests}/[id]/activity,
  each gated on the per-entity .view permission and tenant-checked
  against ctx.portId.
- EntityActivityFeed renders a timeline with action verb ("Updated",
  "Archived"), actor name, relative time, and field old→new diff.
- client-tabs, yacht-tabs, company-tabs, berth-tabs now mount the feed
  on their Activity tab. Interest already has the richer
  InterestTimeline component.
- yacht-tabs YachtInterestsTab also gets a friendlier empty state with
  guidance copy.

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

src/components/companies/company-tabs.tsx

@@ -9,6 +9,7 @@ import { InlineCountryField } from '@/components/shared/inline-country-field';
 import { SubdivisionCombobox } from '@/components/shared/subdivision-combobox';
 import { InlineTagEditor } from '@/components/shared/inline-tag-editor';
 import { NotesList } from '@/components/shared/notes-list';
+import { EntityActivityFeed } from '@/components/shared/entity-activity-feed';
 import { CompanyMembersTab } from '@/components/companies/company-members-tab';
 import { CompanyOwnedYachtsTab } from '@/components/companies/company-owned-yachts-tab';
 import { AddressesEditor, type Address } from '@/components/shared/addresses-editor';
@@ -238,5 +239,15 @@ export function getCompanyTabs({
         <NotesList entityType="companies" entityId={companyId} currentUserId={currentUserId} />
       ),
     },
+    {
+      id: 'activity',
+      label: 'Activity',
+      content: (
+        <EntityActivityFeed
+          endpoint={`/api/v1/companies/${companyId}/activity`}
+          emptyText="No activity recorded for this company yet."
+        />
+      ),
+    },
   ];
 }