feat: 前端分離+功能api化

1. 新增資產管理CRUD、googleOAuth登入
2. 更改原記帳controller

app/Models/InvestmentHolding.php

@@ -0,0 +1,32 @@
+<?php
+
+namespace App\Models;
+
+use Illuminate\Database\Eloquent\Model;
+
+class InvestmentHolding extends Model
+{
+    protected $fillable = [
+        'account_id',
+        'type',
+        'symbol',
+        'name',
+        'shares',
+        'avg_cost',
+    ];
+
+    public function account()
+    {
+        return $this->belongsTo(Account::class);
+    }
+
+    public function transactions()
+    {
+        return $this->hasMany(InvestmentTransaction::class, 'holding_id');
+    }
+
+    public function security()
+    {
+        return $this->hasOne(Security::class, 'code', 'symbol');
+    }
+}