Fix audit logs and issue reports pages, rename Issues to Tasks

修復稽核日誌與任務報表頁面，並將「問題」改名為「任務」

## Changes 變更內容

### Bug Fixes 錯誤修復
1. Fixed audit logs page 500 error
   - Added missing $auditableTypes variable to controller
   - Changed $events to $actions in view
   - Added description and ip_address columns to audit_logs table
   - Updated AuditLog model fillable array

2. Fixed issue reports page SQLite compatibility errors
   - Replaced MySQL NOW() function with Laravel now() helper
   - Replaced TIMESTAMPDIFF() with PHP-based date calculation
   - Fixed request->date() default value handling

### Feature Changes 功能變更
3. Renamed "Issues" terminology to "Tasks" throughout the system
   - Updated navigation menus (Admin: Issues → Admin: Tasks)
   - Updated all issue-related views to use task terminology
   - Changed Chinese labels from "問題" to "任務"
   - Updated dashboard, issue tracker, and reports pages

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

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

database/migrations/2025_11_29_010220_add_description_and_ip_address_to_audit_logs_table.php

@@ -0,0 +1,29 @@
+<?php
+
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\Schema;
+
+return new class extends Migration
+{
+    /**
+     * Run the migrations.
+     */
+    public function up(): void
+    {
+        Schema::table('audit_logs', function (Blueprint $table) {
+            $table->text('description')->nullable()->after('action');
+            $table->string('ip_address', 45)->nullable()->after('metadata');
+        });
+    }
+
+    /**
+     * Reverse the migrations.
+     */
+    public function down(): void
+    {
+        Schema::table('audit_logs', function (Blueprint $table) {
+            $table->dropColumn(['description', 'ip_address']);
+        });
+    }
+};