Add membership fee system with disability discount and fix document permissions

Features:
- Implement two fee types: entrance fee and annual fee (both NT$1,000)
- Add 50% discount for disability certificate holders
- Add disability certificate upload in member profile
- Integrate disability verification into cashier approval workflow
- Add membership fee settings in system admin

Document permissions:
- Fix hard-coded role logic in Document model
- Use permission-based authorization instead of role checks

Additional features:
- Add announcements, general ledger, and trial balance modules
- Add income management and accounting entries
- Add comprehensive test suite with factories
- Update UI translations to Traditional Chinese

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

app/Models/BoardMeeting.php

@@ -0,0 +1,31 @@
+<?php
+
+namespace App\Models;
+
+use Illuminate\Database\Eloquent\Factories\HasFactory;
+use Illuminate\Database\Eloquent\Model;
+use Illuminate\Database\Eloquent\Relations\HasMany;
+
+class BoardMeeting extends Model
+{
+    use HasFactory;
+
+    protected $fillable = [
+        'meeting_date',
+        'title',
+        'notes',
+        'status',
+    ];
+
+    protected $casts = [
+        'meeting_date' => 'date',
+    ];
+
+    /**
+     * Get the finance documents approved by this board meeting.
+     */
+    public function approvedFinanceDocuments(): HasMany
+    {
+        return $this->hasMany(FinanceDocument::class, 'approved_by_board_meeting_id');
+    }
+}