fix(build): extract route.ts handlers to handlers.ts (CLAUDE.md convention)

8 API route files were exporting handler functions directly from route.ts,
which Next.js 15 rejects with "$NAME is not a valid Route export field".
Per CLAUDE.md convention, service-tested handler functions live in sibling
handlers.ts files and route.ts only re-exports the GET/POST/etc. wrapped
in withAuth(withPermission(...)).

Discovered during the mobile-foundation Task 24 build validation; the route
files predate this branch but the build was never re-run on data-model.

Files:
- berth-reservations/[id], companies/autocomplete, companies/[id]/members
  + nested mid/set-primary, yachts/autocomplete, yachts/[id]/transfer,
  yachts/[id]/ownership-history
- Integration tests updated to import from handlers.ts (companies,
  memberships, reservations, yachts-detail)

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

src/app/api/v1/yachts/[id]/ownership-history/handlers.ts

@@ -0,0 +1,14 @@
+import { NextResponse } from 'next/server';
+
+import { type RouteHandler } from '@/lib/api/helpers';
+import { errorResponse } from '@/lib/errors';
+import { listOwnershipHistory } from '@/lib/services/yachts.service';
+
+export const historyHandler: RouteHandler = async (_req, ctx, params) => {
+  try {
+    const history = await listOwnershipHistory(params.id!, ctx.portId);
+    return NextResponse.json({ data: history });
+  } catch (error) {
+    return errorResponse(error);
+  }
+};

src/app/api/v1/yachts/[id]/ownership-history/route.ts

@@ -1,16 +1,5 @@
-import { NextResponse } from 'next/server';
+import { withAuth, withPermission } from '@/lib/api/helpers';
 
-import { withAuth, withPermission, type RouteHandler } from '@/lib/api/helpers';
-import { errorResponse } from '@/lib/errors';
-import { listOwnershipHistory } from '@/lib/services/yachts.service';
-
-export const historyHandler: RouteHandler = async (req, ctx, params) => {
-  try {
-    const history = await listOwnershipHistory(params.id!, ctx.portId);
-    return NextResponse.json({ data: history });
-  } catch (error) {
-    return errorResponse(error);
-  }
-};
+import { historyHandler } from './handlers';
 
 export const GET = withAuth(withPermission('yachts', 'view', historyHandler));

src/app/api/v1/yachts/[id]/transfer/handlers.ts

@@ -0,0 +1,22 @@
+import { NextResponse } from 'next/server';
+
+import { type RouteHandler } from '@/lib/api/helpers';
+import { parseBody } from '@/lib/api/route-helpers';
+import { errorResponse } from '@/lib/errors';
+import { transferOwnership } from '@/lib/services/yachts.service';
+import { transferOwnershipSchema } from '@/lib/validators/yachts';
+
+export const transferHandler: RouteHandler = async (req, ctx, params) => {
+  try {
+    const body = await parseBody(req, transferOwnershipSchema);
+    const yacht = await transferOwnership(params.id!, ctx.portId, body, {
+      userId: ctx.userId,
+      portId: ctx.portId,
+      ipAddress: ctx.ipAddress,
+      userAgent: ctx.userAgent,
+    });
+    return NextResponse.json({ data: yacht });
+  } catch (error) {
+    return errorResponse(error);
+  }
+};

src/app/api/v1/yachts/[id]/transfer/route.ts

@@ -1,24 +1,5 @@
-import { NextResponse } from 'next/server';
+import { withAuth, withPermission } from '@/lib/api/helpers';
 
-import { withAuth, withPermission, type RouteHandler } from '@/lib/api/helpers';
-import { parseBody } from '@/lib/api/route-helpers';
-import { errorResponse } from '@/lib/errors';
-import { transferOwnership } from '@/lib/services/yachts.service';
-import { transferOwnershipSchema } from '@/lib/validators/yachts';
-
-export const transferHandler: RouteHandler = async (req, ctx, params) => {
-  try {
-    const body = await parseBody(req, transferOwnershipSchema);
-    const yacht = await transferOwnership(params.id!, ctx.portId, body, {
-      userId: ctx.userId,
-      portId: ctx.portId,
-      ipAddress: ctx.ipAddress,
-      userAgent: ctx.userAgent,
-    });
-    return NextResponse.json({ data: yacht });
-  } catch (error) {
-    return errorResponse(error);
-  }
-};
+import { transferHandler } from './handlers';
 
 export const POST = withAuth(withPermission('yachts', 'transfer', transferHandler));