feat: 实现城市手册项目需求 - 数据库模型

- 扩展 User 模型，添加角色和状态字段
- 创建 Region 模型（省市县乡村层级结构）
- 创建版主管理相关模型（申请、权限、支持、限制）
- 创建 Article 模型（文章 + 审核流程）
- 创建 FeaturedService 模型（特色服务 + 审核流程）
- 创建交互功能模型（评论、评分、点赞、收藏）
- 更新 Django settings 注册所有 apps
- 创建需求实施文档

完整实现需求文档中的 12 个核心数据表和审核流程

backend/apps/moderation/__init__.py

@@ -0,0 +1 @@
+# Moderation app

backend/apps/moderation/apps.py

@@ -0,0 +1,7 @@
+from django.apps import AppConfig
+
+
+class ModerationConfig(AppConfig):
+    default_auto_field = 'django.db.models.BigAutoField'
+    name = 'apps.moderation'
+    verbose_name = '版主管理'

backend/apps/moderation/models.py

@@ -0,0 +1,190 @@
+from django.db import models
+from django.conf import settings
+from apps.regions.models import Region
+
+
+class ModeratorApplication(models.Model):
+    """Model for moderator applications."""
+
+    STATUS_CHOICES = [
+        ('pending', '待审核'),
+        ('approved', '已通过'),
+        ('rejected', '已拒绝'),
+        ('cancelled', '已取消'),
+    ]
+
+    RANK_CHOICES = [
+        ('general', '将军'),
+        ('colonel', '校官'),
+        ('captain', '尉官'),
+        ('soldier', '士兵'),
+    ]
+
+    applicant = models.ForeignKey(
+        settings.AUTH_USER_MODEL,
+        on_delete=models.CASCADE,
+        related_name='moderator_applications',
+        verbose_name='申请者'
+    )
+    region = models.ForeignKey(
+        Region,
+        on_delete=models.CASCADE,
+        related_name='moderator_applications',
+        verbose_name='申请的版块'
+    )
+    support_count = models.IntegerField(default=0, verbose_name='支持人数')
+    deadline = models.DateTimeField(verbose_name='截止时间')
+    status = models.CharField(max_length=20, choices=STATUS_CHOICES, default='pending', verbose_name='状态')
+    rank = models.CharField(max_length=20, choices=RANK_CHOICES, verbose_name='军衔级别')
+    reviewed_by = models.ForeignKey(
+        settings.AUTH_USER_MODEL,
+        on_delete=models.SET_NULL,
+        null=True,
+        blank=True,
+        related_name='reviewed_applications',
+        verbose_name='审核人'
+    )
+    reviewed_at = models.DateTimeField(null=True, blank=True, verbose_name='审核时间')
+    created_at = models.DateTimeField(auto_now_add=True, verbose_name='申请时间')
+
+    class Meta:
+        db_table = 'moderator_applications'
+        verbose_name = '版主申请'
+        verbose_name_plural = '版主申请'
+        ordering = ['-created_at']
+
+    def __str__(self):
+        return f'{self.applicant.username} - {self.region.name} ({self.get_status_display()})'
+
+    def is_expired(self):
+        """Check if the application has expired."""
+        from django.utils import timezone
+        return timezone.now() > self.deadline
+
+    def has_enough_support(self):
+        """Check if the application has enough support."""
+        # TODO: Define minimum support count
+        return self.support_count >= 10
+
+
+class ModeratorPermission(models.Model):
+    """Model for moderator permissions."""
+
+    PERMISSION_STATUS_CHOICES = [
+        ('active', '正常'),
+        ('restricted', '限制'),
+        ('revoked', '取消'),
+    ]
+
+    RANK_CHOICES = [
+        ('general', '将军'),
+        ('colonel', '校官'),
+        ('captain', '尉官'),
+        ('soldier', '士兵'),
+    ]
+
+    moderator = models.ForeignKey(
+        settings.AUTH_USER_MODEL,
+        on_delete=models.CASCADE,
+        related_name='moderator_permissions',
+        verbose_name='版主'
+    )
+    region = models.ForeignKey(
+        Region,
+        on_delete=models.CASCADE,
+        related_name='moderator_permissions',
+        verbose_name='管辖版块'
+    )
+    rank = models.CharField(max_length=20, choices=RANK_CHOICES, verbose_name='军衔级别')
+    status = models.CharField(
+        max_length=20,
+        choices=PERMISSION_STATUS_CHOICES,
+        default='active',
+        verbose_name='权限状态'
+    )
+    created_at = models.DateTimeField(auto_now_add=True, verbose_name='创建时间')
+    restricted_until = models.DateTimeField(null=True, blank=True, verbose_name='限制结束时间')
+
+    class Meta:
+        db_table = 'moderator_permissions'
+        verbose_name = '版主权限'
+        verbose_name_plural = '版主权限'
+        ordering = ['-created_at']
+
+    def __str__(self):
+        return f'{self.moderator.username} - {self.region.name} ({self.get_status_display()})'
+
+    def is_active(self):
+        """Check if the permission is currently active."""
+        from django.utils import timezone
+        if self.status != 'active':
+            return False
+        if self.restricted_until and timezone.now() < self.restricted_until:
+            return False
+        return True
+
+
+class ModeratorSupport(models.Model):
+    """Model for moderator application supports."""
+
+    supporter = models.ForeignKey(
+        settings.AUTH_USER_MODEL,
+        on_delete=models.CASCADE,
+        related_name='supported_applications',
+        verbose_name='支持者'
+    )
+    application = models.ForeignKey(
+        ModeratorApplication,
+        on_delete=models.CASCADE,
+        related_name='supports',
+        verbose_name='版主申请'
+    )
+    created_at = models.DateTimeField(auto_now_add=True, verbose_name='支持时间')
+
+    class Meta:
+        db_table = 'moderator_supports'
+        verbose_name = '版主支持'
+        verbose_name_plural = '版主支持'
+        unique_together = ['supporter', 'application']
+
+    def __str__(self):
+        return f'{self.supporter.username} supports {self.application.region.name}'
+
+
+class PermissionRestriction(models.Model):
+    """Model for permission restrictions."""
+
+    RESTRICTION_TYPE_CHOICES = [
+        ('partial', '部分限制'),
+        ('full', '完全限制'),
+    ]
+
+    operator = models.ForeignKey(
+        settings.AUTH_USER_MODEL,
+        on_delete=models.CASCADE,
+        related_name='created_restrictions',
+        verbose_name='操作者'
+    )
+    target_moderator = models.ForeignKey(
+        settings.AUTH_USER_MODEL,
+        on_delete=models.CASCADE,
+        related_name='received_restrictions',
+        verbose_name='被限制版主'
+    )
+    restriction_type = models.CharField(
+        max_length=20,
+        choices=RESTRICTION_TYPE_CHOICES,
+        verbose_name='限制类型'
+    )
+    start_time = models.DateTimeField(verbose_name='限制开始时间')
+    end_time = models.DateTimeField(verbose_name='限制结束时间')
+    created_at = models.DateTimeField(auto_now_add=True, verbose_name='创建时间')
+
+    class Meta:
+        db_table = 'permission_restrictions'
+        verbose_name = '权限限制'
+        verbose_name_plural = '权限限制'
+        ordering = ['-created_at']
+
+    def __str__(self):
+        return f'{self.operator.username} restricted {self.target_moderator.username} ({self.get_restriction_type_display()})'