feat(models): 组织、用户、角色、客户、会话与消息模型

按组织边界定义数据关系，补齐仓储层与通用工具，迁移脚本可重复执行。

backend/app/models/schemas/agent.py

@@ -0,0 +1,163 @@
+"""
+Copyright 2024-2026 ChatterMate
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+"""
+
+from datetime import datetime
+from pydantic import BaseModel, Field
+from typing import List, Optional, Dict
+from enum import Enum
+from uuid import UUID
+from app.models.agent import AgentType
+from app.agents.guardrail_policy import GUARDRAIL_PROMPT_MAX
+from app.models.schemas.agent_customization import CustomizationResponse
+from app.models.schemas.user_group import UserGroupResponse
+
+class KnowledgeItem(BaseModel):
+    id: int
+    name: str
+    type: str
+
+
+class AgentBase(BaseModel):
+    name: str = Field(..., min_length=1, max_length=100)
+    description: Optional[str] = None
+    agent_type: AgentType
+    instructions: List[str]
+    tools: Optional[List[Dict]] = None
+    is_active: bool = True
+    is_default: bool = False
+    transfer_to_human: bool = False
+    ai_replies_enabled: bool = True
+    channel_quick_replies: bool = False
+    ask_for_rating: bool = False
+    handoff_collect_email: bool = True
+    handoff_collect_name: bool = True
+    enable_rate_limiting: bool = False
+    overall_limit_per_ip: int = Field(default=100, description="Maximum number of requests allowed per IP address")
+    requests_per_sec: float = Field(default=1.0, description="Number of requests allowed per second")
+    use_workflow: bool = False
+    active_workflow_id: Optional[UUID] = None
+    display_name: Optional[str] = None
+    allow_attachments: bool = False
+    allowed_attachment_types: Optional[List[str]] = Field(
+        default=None,
+        description="List of allowed attachment type categories: 'images', 'documents', 'office', 'text'. If null/empty, all types allowed."
+    )
+    require_token_auth: bool = False
+    ticketing_enabled: bool = True
+    topic_scope: Optional[str] = Field(
+        default=None, max_length=500,
+        description="Optional one-line business remit used by the platform guardrail's topic-scope line."
+    )
+    guardrail_prompt: Optional[str] = Field(
+        default=None, max_length=GUARDRAIL_PROMPT_MAX,
+        description="Scope rule for this agent. Null uses the platform default; edit it to fit your business."
+    )
+    guardrail_enabled: bool = Field(
+        default=True,
+        description="Apply the scope rule. Injection and disclosure protections are always on."
+    )
+
+
+class AgentCreate(AgentBase):
+    organization_id: Optional[UUID] = None
+
+
+class AgentUpdate(BaseModel):
+    display_name: Optional[str] = None
+    instructions: Optional[List[str]] = None
+    is_active: Optional[bool] = None
+    transfer_to_human: Optional[bool] = None
+    ai_replies_enabled: Optional[bool] = None
+    channel_quick_replies: Optional[bool] = None
+    ask_for_rating: Optional[bool] = None
+    handoff_collect_email: Optional[bool] = None
+    handoff_collect_name: Optional[bool] = None
+    enable_rate_limiting: Optional[bool] = None
+    overall_limit_per_ip: Optional[int] = None
+    requests_per_sec: Optional[float] = None
+    use_workflow: Optional[bool] = None
+    active_workflow_id: Optional[UUID] = None
+    allow_attachments: Optional[bool] = None
+    allowed_attachment_types: Optional[List[str]] = Field(
+        default=None,
+        description="List of allowed attachment type categories: 'images', 'documents', 'office', 'text'. If null/empty, all types allowed."
+    )
+    require_token_auth: Optional[bool] = None
+    ticketing_enabled: Optional[bool] = None
+    topic_scope: Optional[str] = Field(default=None, max_length=500)
+    guardrail_prompt: Optional[str] = Field(default=None, max_length=GUARDRAIL_PROMPT_MAX)
+    guardrail_enabled: Optional[bool] = None
+
+
+class AgentKnowledge(BaseModel):
+    id: int
+    name: str
+    type: str
+
+
+class AgentRosterItem(BaseModel):
+    """An AI agent as the inbox filter needs it: a name to group chats by.
+
+    Deliberately none of AgentResponse's configuration — `instructions`, and
+    especially `guardrail_prompt`, which tells a reader how to phrase a bypass.
+    """
+    id: UUID
+    name: str
+    display_name: Optional[str] = None
+    is_active: bool = True
+
+    class Config:
+        from_attributes = True
+
+
+class AgentResponse(BaseModel):
+    id: UUID
+    name: str
+    display_name: Optional[str]
+    description: Optional[str]
+    agent_type: AgentType
+    instructions: List[str]
+    is_active: bool
+    organization_id: UUID
+    knowledge: List[AgentKnowledge] = []
+    transfer_to_human: bool = False
+    ai_replies_enabled: bool = True
+    channel_quick_replies: bool = False
+    ask_for_rating: bool = False
+    handoff_collect_email: bool = True
+    handoff_collect_name: bool = True
+    enable_rate_limiting: Optional[bool] = None
+    overall_limit_per_ip: Optional[int] = None
+    requests_per_sec: Optional[float] = None
+    use_workflow: Optional[bool] = False
+    active_workflow_id: Optional[UUID] = None
+    allow_attachments: bool = False
+    allowed_attachment_types: Optional[List[str]] = None
+    require_token_auth: bool = False
+    ticketing_enabled: bool = True
+    topic_scope: Optional[str] = None
+    guardrail_prompt: Optional[str] = None
+    guardrail_enabled: bool = True
+    created_at: Optional[datetime] = None
+    updated_at: Optional[datetime] = None
+
+    class Config:
+        from_attributes = True
+
+
+class AgentWithCustomizationResponse(AgentResponse):
+    customization: Optional[CustomizationResponse] = None
+    groups: List[UserGroupResponse] = []