feat: implement automation module

- Event-based triggers (Phase 1):
  - Trigger/TriggerLog models with field_change type
  - TriggerService for condition evaluation and action execution
  - Trigger CRUD API endpoints
  - Task integration (status, assignee, priority changes)
  - Frontend: TriggerList, TriggerForm components

- Weekly reports (Phase 2):
  - ScheduledReport/ReportHistory models
  - ReportService for stats generation
  - APScheduler for Friday 16:00 job
  - Report preview/generate/history API
  - Frontend: WeeklyReportPreview, ReportHistory components

- Tests: 23 new tests (14 triggers + 9 reports)
- OpenSpec: add-automation change archived

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

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

backend/app/schemas/trigger.py

@@ -0,0 +1,82 @@
+from datetime import datetime
+from typing import Optional, List, Dict, Any
+from pydantic import BaseModel, Field
+
+
+class TriggerCondition(BaseModel):
+    field: str = Field(..., description="Field to check: status_id, assignee_id, priority")
+    operator: str = Field(..., description="Operator: equals, not_equals, changed_to, changed_from")
+    value: str = Field(..., description="Value to compare against")
+
+
+class TriggerAction(BaseModel):
+    type: str = Field(default="notify", description="Action type: notify")
+    target: str = Field(default="assignee", description="Target: assignee, creator, project_owner, user:<id>")
+    template: Optional[str] = Field(None, description="Message template with variables")
+
+
+class TriggerCreate(BaseModel):
+    name: str = Field(..., min_length=1, max_length=200)
+    description: Optional[str] = Field(None, max_length=2000)
+    trigger_type: str = Field(default="field_change")
+    conditions: TriggerCondition
+    actions: List[TriggerAction]
+    is_active: bool = Field(default=True)
+
+
+class TriggerUpdate(BaseModel):
+    name: Optional[str] = Field(None, min_length=1, max_length=200)
+    description: Optional[str] = Field(None, max_length=2000)
+    conditions: Optional[TriggerCondition] = None
+    actions: Optional[List[TriggerAction]] = None
+    is_active: Optional[bool] = None
+
+
+class TriggerUserInfo(BaseModel):
+    id: str
+    name: str
+    email: str
+
+    class Config:
+        from_attributes = True
+
+
+class TriggerResponse(BaseModel):
+    id: str
+    project_id: str
+    name: str
+    description: Optional[str]
+    trigger_type: str
+    conditions: Dict[str, Any]
+    actions: List[Dict[str, Any]]
+    is_active: bool
+    created_by: Optional[str]
+    created_at: datetime
+    updated_at: datetime
+    creator: Optional[TriggerUserInfo] = None
+
+    class Config:
+        from_attributes = True
+
+
+class TriggerListResponse(BaseModel):
+    triggers: List[TriggerResponse]
+    total: int
+
+
+class TriggerLogResponse(BaseModel):
+    id: str
+    trigger_id: str
+    task_id: Optional[str]
+    executed_at: datetime
+    status: str
+    details: Optional[Dict[str, Any]]
+    error_message: Optional[str]
+
+    class Config:
+        from_attributes = True
+
+
+class TriggerLogListResponse(BaseModel):
+    logs: List[TriggerLogResponse]
+    total: int