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/ticket_settings.py

@@ -0,0 +1,100 @@
+"""
+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 sqlalchemy import JSON, Boolean, Column, DateTime, Float, ForeignKey, Integer, String, Text
+from sqlalchemy.dialects.postgresql import UUID
+from sqlalchemy.orm import relationship
+from sqlalchemy.sql import expression, func
+
+from app.database import Base
+
+# Staged autonomy levels — enforced in code (TicketService/worker), never just
+# in the prompt.
+AUTONOMY_INVESTIGATE_ONLY = 1   # L1: investigate + summarize
+AUTONOMY_PROPOSE_APPROVE = 2    # L2: propose resolution, human approves
+AUTONOMY_AUTO_RESOLVE = 3       # L3: auto-resolve + notify customer
+
+# Default customer message templates. [customer]/[ticket] placeholders are
+# substituted at send time.
+DEFAULT_CREATED_TEMPLATE = (
+    "Hi [customer] — we've opened ticket [ticket] about your issue and our "
+    "team is on it. We'll keep you posted."
+)
+DEFAULT_RESOLVED_TEMPLATE = (
+    "Good news [customer] — ticket [ticket] is resolved. Here's what happened "
+    "and what we did to fix it. Reply if anything's still off."
+)
+
+# Default SLA targets in minutes, keyed by priority value.
+DEFAULT_SLA_TARGETS = {
+    "urgent": {"first_response_minutes": 15, "resolution_minutes": 120},
+    "high": {"first_response_minutes": 30, "resolution_minutes": 240},
+    "medium": {"first_response_minutes": 120, "resolution_minutes": 1440},
+    "low": {"first_response_minutes": 480, "resolution_minutes": 4320},
+}
+
+
+class OrganizationTicketSettings(Base):
+    """Per-org AI ticketing policy: autonomy level, SLA targets, customer
+    comms templates and investigation budgets. One row per organization,
+    created lazily with defaults on first read.
+    """
+    __tablename__ = "organization_ticket_settings"
+
+    organization_id = Column(
+        UUID(as_uuid=True),
+        ForeignKey("organizations.id", ondelete="CASCADE"),
+        primary_key=True,
+    )
+
+    autonomy_level = Column(Integer, nullable=False, default=AUTONOMY_INVESTIGATE_ONLY, server_default="1")
+    auto_investigate_on_create = Column(Boolean, nullable=False, default=True, server_default=expression.true())
+    min_confidence_to_auto_resolve = Column(Float, nullable=False, default=0.85)
+    # resolved_pending_confirmation -> closed after this many hours without a
+    # customer reply.
+    confirmation_timeout_hours = Column(Integer, nullable=False, default=72, server_default="72")
+    csat_enabled = Column(Boolean, nullable=False, default=True, server_default=expression.true())
+
+    # {"urgent": {"first_response_minutes": 15, "resolution_minutes": 120}, ...}
+    sla_targets = Column(JSON, nullable=True)
+    # Customer message templates with [customer]/[ticket] placeholders.
+    created_template = Column(Text, nullable=True)
+    resolved_template = Column(Text, nullable=True)
+
+    # Jira escalation (one-way sync). jira_escalation_priority is the minimum
+    # priority value that also syncs to Jira.
+    jira_escalation_enabled = Column(Boolean, nullable=False, default=False, server_default=expression.false())
+    jira_escalation_priority = Column(String, nullable=True)
+
+    # Ticket-scoped MCP connector selection (list of mcp_tools.id) —
+    # deliberately separate from the chat-facing MCPToolToAgent m2m so
+    # observability connectors are never handed to the customer-facing agent.
+    investigation_mcp_tool_ids = Column(JSON, nullable=True)
+    # Alert-webhook intake: Grafana/Datadog/CloudWatch alerts auto-open
+    # tickets via POST /tickets/webhooks/alerts/{org_id}/{secret}.
+    alert_webhook_enabled = Column(Boolean, nullable=False, default=False, server_default=expression.false())
+    # URL-path token authenticating alert posts; rotated by re-enabling.
+    alert_webhook_secret = Column(String(64), nullable=True)
+
+    # Investigation budgets.
+    max_tool_calls_per_run = Column(Integer, nullable=False, default=25, server_default="25")
+    max_runs_per_ticket = Column(Integer, nullable=False, default=3, server_default="3")
+    monthly_investigation_cap = Column(Integer, nullable=True)
+
+    created_at = Column(DateTime(timezone=True), server_default=func.now())
+    updated_at = Column(DateTime(timezone=True), onupdate=func.now())
+
+    organization = relationship("Organization")