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/AccountingEntry.php

@@ -0,0 +1,101 @@
+<?php
+
+namespace App\Models;
+
+use Illuminate\Database\Eloquent\Factories\HasFactory;
+use Illuminate\Database\Eloquent\Model;
+
+class AccountingEntry extends Model
+{
+    use HasFactory;
+
+    const ENTRY_TYPE_DEBIT = 'debit';
+    const ENTRY_TYPE_CREDIT = 'credit';
+
+    protected $fillable = [
+        'finance_document_id',
+        'income_id',
+        'chart_of_account_id',
+        'entry_type',
+        'amount',
+        'entry_date',
+        'description',
+    ];
+
+    protected $casts = [
+        'entry_date' => 'date',
+        'amount' => 'decimal:2',
+    ];
+
+    /**
+     * Get the finance document that owns this entry
+     */
+    public function financeDocument()
+    {
+        return $this->belongsTo(FinanceDocument::class);
+    }
+
+    /**
+     * Get the income that owns this entry
+     */
+    public function income()
+    {
+        return $this->belongsTo(Income::class);
+    }
+
+    /**
+     * Get the chart of account for this entry
+     */
+    public function chartOfAccount()
+    {
+        return $this->belongsTo(ChartOfAccount::class);
+    }
+
+    /**
+     * Check if this is a debit entry
+     */
+    public function isDebit(): bool
+    {
+        return $this->entry_type === self::ENTRY_TYPE_DEBIT;
+    }
+
+    /**
+     * Check if this is a credit entry
+     */
+    public function isCredit(): bool
+    {
+        return $this->entry_type === self::ENTRY_TYPE_CREDIT;
+    }
+
+    /**
+     * Scope to filter debit entries
+     */
+    public function scopeDebits($query)
+    {
+        return $query->where('entry_type', self::ENTRY_TYPE_DEBIT);
+    }
+
+    /**
+     * Scope to filter credit entries
+     */
+    public function scopeCredits($query)
+    {
+        return $query->where('entry_type', self::ENTRY_TYPE_CREDIT);
+    }
+
+    /**
+     * Scope to filter by account
+     */
+    public function scopeForAccount($query, $accountId)
+    {
+        return $query->where('chart_of_account_id', $accountId);
+    }
+
+    /**
+     * Scope to filter by date range
+     */
+    public function scopeDateRange($query, $startDate, $endDate)
+    {
+        return $query->whereBetween('entry_date', [$startDate, $endDate]);
+    }
+}