feat: implement global search API functionality

[Oluwasuyi-Timilehin]

#closes #476

Summary

This pull request adds a new global search API endpoint to the dashboard. The endpoint searches across employees, invoices, and fiat transactions concurrently and returns a categorized JSON response.

Files Added

• src/server/services/search.service.ts
• src/app/api/v1/dashboard/search/route.ts

What Changed

• Added SearchService.globalSearch() to perform concurrent database queries using Promise.all.
• Implemented case-insensitive matching for:
  • Employee first and last names
  • Invoice numbers
  • Transaction reference and provider reference values
• Added GET /api/v1/dashboard/search?q={query}
• Added authentication enforcement via AuthUtils.authenticateRequest().
• Returned structured categories: employees, invoices, and transactions.

Testing Steps

1. Install dependencies if needed:

   corepack pnpm install

2. Run the app in development mode:

   corepack pnpm dev

3. Send a request to the new endpoint with a valid Bearer token:

   curl "http://localhost:3000/api/v1/dashboard/search?q=alice" \
     -H "Authorization: Bearer YOUR_ACCESS_TOKEN"

4. Confirm the response includes:
   • success: true
   • data.employees
   • data.invoices
   • data.transactions
5. Validate search behavior:
   • Search by employee name returns employee results
   • Search by invoice number returns invoice results
   • Search by transaction reference returns transaction results
6. Confirm invalid or missing q returns an error response.

Notes

• The endpoint uses a maximum limit of 10 results per category.
• If the authenticated user has no organizationId, the endpoint returns empty categories.

#closes

[vercel]

@Oluwasuyi-Timilehin is attempting to deploy a commit to the vestroll's projects Team on Vercel.

A member of the Team first needs to authorize it.

[codeZe-us]

@Oluwasuyi-Timilehin PR should point to dev branch not main branch

[Oluwasuyi-Timilehin]

@codeZe-us I already pointed the pr to the dev branch