feat(note): add audio upload and sharing functionality

- Introduced `note_audio` table for storing audio attachments related to notes.
- Implemented audio upload endpoint in `Note` controller to handle audio file uploads.
- Added sharing functionality with `note_share` table to manage share tokens and view counts.
- Updated API routes to include endpoints for audio uploads and share creation.
- Enhanced documentation to reflect new audio and sharing features.

app/note/model/NoteAudio.php

@@ -0,0 +1,27 @@
+<?php
+declare(strict_types=1);
+
+namespace app\note\model;
+
+use think\Model;
+
+/**
+ * note 模块录音附件模型
+ */
+class NoteAudio extends Model
+{
+    protected $connection = 'dbnote';
+
+    protected $name = 'note_audio';
+
+    protected $pk = 'id';
+
+    protected $autoWriteTimestamp = false;
+
+    public static function findLatestByNoteId(int $noteId): ?self
+    {
+        return self::where('note_id', $noteId)
+            ->order('id', 'desc')
+            ->find();
+    }
+}