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>

database/migrations/2026_07_18_090000_create_care_practitioner_branch_table.php

@@ -0,0 +1,37 @@
+<?php
+
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\DB;
+use Illuminate\Support\Facades\Schema;
+
+return new class extends Migration
+{
+    public function up(): void
+    {
+        Schema::create('care_practitioner_branch', function (Blueprint $table) {
+            $table->id();
+            $table->foreignId('practitioner_id')->constrained('care_practitioners')->cascadeOnDelete();
+            $table->foreignId('branch_id')->constrained('care_branches')->cascadeOnDelete();
+            $table->timestamps();
+
+            $table->unique(['practitioner_id', 'branch_id']);
+        });
+
+        // Backfill explicit assignments from the legacy single branch_id (never invent "all branches").
+        $now = now();
+        foreach (DB::table('care_practitioners')->whereNotNull('branch_id')->get(['id', 'branch_id']) as $row) {
+            DB::table('care_practitioner_branch')->insertOrIgnore([
+                'practitioner_id' => $row->id,
+                'branch_id' => $row->branch_id,
+                'created_at' => $now,
+                'updated_at' => $now,
+            ]);
+        }
+    }
+
+    public function down(): void
+    {
+        Schema::dropIfExists('care_practitioner_branch');
+    }
+};