feat: supplier modal wizard, pipeline delete, sidebar cleanup

- Replace two-tab supplier selector with two-step wizard (method select → suppliers → summary)
- Add per-item channel picker (Email / WhatsApp / Both) in By Item mode
- Add confirmation summary step before submitting By Item supplier assignments
- Add type-to-confirm delete on pipeline list rows
- Redirect purchase.requests.index to pipeline (same data, single entry point)
- Remove Purchase Requests from sidebar nav
- Add edit-request-modal, supplier-invite-list components
- Add address coordinates migration for settings_locations

Co-Authored-By: Claude Sonnet 4.6 <[email protected]>

app/Http/Controllers/Purchase/PurchaseRequestController.php

@@ -12,9 +12,7 @@ class PurchaseRequestController extends Controller
 {
     public function index()
     {
-        $requests = PurchaseRequest::with(['requestedBy', 'items'])->latest()->paginate(15);
-
-        return view('purchase.requests.index', compact('requests'));
+        return redirect()->route('purchase.pipeline.index');
     }
 
     public function create()