feat: add theme preset system with admin CRUD, public listing, and user theme settings

- Add ChromaticColor (17 Tailwind colors) and NeutralColor (5 grays) enums
- Add ThemePreset table with flat color columns and unique name constraint
- Add admin theme endpoints (CRUD + set default) at /api/v1/admin/theme
- Add public theme listing at /api/v1/site/themes
- Add user theme settings (PATCH /theme) with color snapshot on User model
- User.color_* columns store per-user overrides; fallback to default preset then builtin
- Initialize default theme preset in migration
- Remove legacy defaultTheme/themes settings

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

routers/api/v1/trash/__init__.py

@@ -0,0 +1,161 @@
+"""
+回收站路由
+
+提供回收站管理功能：列出、恢复、永久删除、清空。
+
+路由前缀：/trash
+"""
+from typing import Annotated
+
+from fastapi import APIRouter, Depends
+from loguru import logger as l
+
+from middleware.auth import auth_required
+from middleware.dependencies import SessionDep
+from sqlmodels import Object, User
+from sqlmodels.object import TrashDeleteRequest, TrashItemResponse, TrashRestoreRequest
+from service.storage.object import (
+    permanently_delete_objects,
+    restore_objects,
+    soft_delete_objects,
+)
+
+trash_router = APIRouter(
+    prefix="/trash",
+    tags=["trash"],
+)
+
+
+@trash_router.get(
+    path='/',
+    summary='列出回收站内容',
+    description='获取当前用户回收站中的所有顶层对象。',
+)
+async def router_trash_list(
+    session: SessionDep,
+    user: Annotated[User, Depends(auth_required)],
+) -> list[TrashItemResponse]:
+    """
+    列出回收站内容
+
+    认证：需要 JWT token
+
+    返回回收站中被直接删除的顶层对象列表，
+    不包含其子对象（子对象在恢复/永久删除时会随顶层对象一起处理）。
+    """
+    items = await Object.get_trash_items(session, user.id)
+
+    return [
+        TrashItemResponse(
+            id=item.id,
+            name=item.name,
+            type=item.type,
+            size=item.size,
+            deleted_at=item.deleted_at,
+            original_parent_id=item.deleted_original_parent_id,
+        )
+        for item in items
+    ]
+
+
+@trash_router.patch(
+    path='/restore',
+    summary='恢复对象',
+    description='从回收站恢复一个或多个对象到原位置。如果原位置不存在则恢复到根目录。',
+    status_code=204,
+)
+async def router_trash_restore(
+    session: SessionDep,
+    user: Annotated[User, Depends(auth_required)],
+    request: TrashRestoreRequest,
+) -> None:
+    """
+    从回收站恢复对象
+
+    认证：需要 JWT token
+
+    流程：
+    1. 验证对象存在且在回收站中（deleted_at IS NOT NULL）
+    2. 检查原父目录是否存在且未删除
+    3. 存在 → 恢复到原位置；不存在 → 恢复到根目录
+    4. 处理同名冲突（自动重命名）
+    5. 清除 deleted_at 和 deleted_original_parent_id
+    """
+    user_id = user.id
+    objects_to_restore: list[Object] = []
+
+    for obj_id in request.ids:
+        obj = await Object.get(
+            session,
+            (Object.id == obj_id) & (Object.owner_id == user_id) & (Object.deleted_at != None)
+        )
+        if obj:
+            objects_to_restore.append(obj)
+
+    if objects_to_restore:
+        restored_count = await restore_objects(session, objects_to_restore, user_id)
+        l.info(f"用户 {user_id} 从回收站恢复了 {restored_count} 个对象")
+
+
+@trash_router.delete(
+    path='/',
+    summary='永久删除对象',
+    description='永久删除回收站中的指定对象，包括物理文件和数据库记录。',
+    status_code=204,
+)
+async def router_trash_delete(
+    session: SessionDep,
+    user: Annotated[User, Depends(auth_required)],
+    request: TrashDeleteRequest,
+) -> None:
+    """
+    永久删除回收站中的对象
+
+    认证：需要 JWT token
+
+    流程：
+    1. 验证对象存在且在回收站中
+    2. BFS 收集所有子文件的 PhysicalFile
+    3. 处理引用计数，引用为 0 时物理删除文件
+    4. 硬删除根 Object（CASCADE 清理子对象）
+    5. 更新用户存储配额
+    """
+    user_id = user.id
+    objects_to_delete: list[Object] = []
+
+    for obj_id in request.ids:
+        obj = await Object.get(
+            session,
+            (Object.id == obj_id) & (Object.owner_id == user_id) & (Object.deleted_at != None)
+        )
+        if obj:
+            objects_to_delete.append(obj)
+
+    if objects_to_delete:
+        deleted_count = await permanently_delete_objects(session, objects_to_delete, user_id)
+        l.info(f"用户 {user_id} 永久删除了 {deleted_count} 个对象")
+
+
+@trash_router.delete(
+    path='/empty',
+    summary='清空回收站',
+    description='永久删除回收站中的所有对象。',
+    status_code=204,
+)
+async def router_trash_empty(
+    session: SessionDep,
+    user: Annotated[User, Depends(auth_required)],
+) -> None:
+    """
+    清空回收站
+
+    认证：需要 JWT token
+
+    获取回收站中所有顶层对象，逐个执行永久删除。
+    """
+    user_id = user.id
+    trash_items = await Object.get_trash_items(session, user_id)
+
+    if trash_items:
+        deleted_count = await permanently_delete_objects(session, trash_items, user_id)
+        l.info(f"用户 {user_id} 清空回收站，共删除 {deleted_count} 个对象")