Allow explicit multi-branch practitioner assignment for telemedicine.

Replace optional “All branches” with required branch checkboxes; doctors may switch only among assigned sites, never org-wide by default.

Co-authored-by: Cursor <cursoragent@cursor.com>

tests/Feature/CareStaffTenantScopeTest.php

@@ -77,6 +77,7 @@ class CareStaffTenantScopeTest extends TestCase
             'name' => 'Demo Pro Doctor',
             'is_active' => true,
         ]);
+        $mine->syncAssignedBranches([$branch->id]);
 
         $other = Practitioner::create([
             'owner_ref' => $owner->public_id,
@@ -85,6 +86,7 @@ class CareStaffTenantScopeTest extends TestCase
             'name' => 'Other Doctor',
             'is_active' => true,
         ]);
+        $other->syncAssignedBranches([$branch->id]);
 
         $assignedPatient = Patient::create([
             'uuid' => (string) \Illuminate\Support\Str::uuid(),