feat: add GitHub username field and implement commit filtering by author in intern dashboard

database/migrations/2026_07_01_203644_add_github_username_to_career_applications_table.php

@@ -0,0 +1,28 @@
+<?php
+
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\Schema;
+
+return new class extends Migration
+{
+    /**
+     * Run the migrations.
+     */
+    public function up(): void
+    {
+        Schema::table('career_applications', function (Blueprint $table) {
+            $table->string('github_username')->nullable()->after('github_repo');
+        });
+    }
+
+    /**
+     * Reverse the migrations.
+     */
+    public function down(): void
+    {
+        Schema::table('career_applications', function (Blueprint $table) {
+            $table->dropColumn('github_username');
+        });
+    }
+};