feat(01-01): add Member notes relationship, morph map, and NoteFactory

- Add notes() morphMany relationship to Member model (ordered by created_at desc)
- Register morph map in AppServiceProvider ('member' => Member::class)
- Create NoteFactory with forMember() and byAuthor() state methods

database/factories/NoteFactory.php

@@ -0,0 +1,44 @@
+<?php
+
+namespace Database\Factories;
+
+use App\Models\Member;
+use App\Models\Note;
+use App\Models\User;
+use Illuminate\Database\Eloquent\Factories\Factory;
+
+class NoteFactory extends Factory
+{
+    protected $model = Note::class;
+
+    public function definition(): array
+    {
+        return [
+            'notable_type' => 'member', // Uses morph map alias
+            'notable_id' => Member::factory(),
+            'content' => $this->faker->paragraph(),
+            'author_user_id' => User::factory(),
+        ];
+    }
+
+    /**
+     * Set the note to belong to a specific member
+     */
+    public function forMember(Member $member): static
+    {
+        return $this->state(fn () => [
+            'notable_type' => 'member',
+            'notable_id' => $member->id,
+        ]);
+    }
+
+    /**
+     * Set the note to be authored by a specific user
+     */
+    public function byAuthor(User $user): static
+    {
+        return $this->state(fn () => [
+            'author_user_id' => $user->id,
+        ]);
+    }
+}