feat(backend): Phase 0 项目骨架完成 — 后端/前端/数据库/Docker

- 后端：FastAPI + SQLAlchemy + Alembic，7 张核心表迁移成功
- 前端：Next.js 16 + TailwindCSS 4 + 三端布局（投资人/创始人/Admin）
- 数据库：PostgreSQL 16，7 张核心实体表（tenants/users/companies/monthly_reports/health_scores/risk_events/audit_logs）
- Docker：docker-compose.yml + 前后端 Dockerfile
- 测试：健康检查 4 个测试全部 GREEN
- 文档：README/run.md/AGENTS.md/docs 体系完整

backend/app/models/report.py

@@ -0,0 +1,44 @@
+"""月报模型。
+
+被投企业按月提交的经营报告，支持 AI 解析。
+"""
+
+import uuid
+from datetime import datetime, timezone
+
+from sqlalchemy import DateTime, ForeignKey, Integer, String, Text
+from sqlalchemy.dialects.postgresql import JSONB
+from sqlalchemy.orm import Mapped, mapped_column
+
+from app.core.database import Base
+
+
+class MonthlyReport(Base):
+    """月报。"""
+
+    __tablename__ = "monthly_reports"
+
+    id: Mapped[str] = mapped_column(String(36), primary_key=True, default=lambda: str(uuid.uuid4()))
+    company_id: Mapped[str] = mapped_column(String(36), ForeignKey("companies.id"), nullable=False, index=True)
+    period_year: Mapped[int] = mapped_column(Integer, nullable=False, comment="报告年份")
+    period_month: Mapped[int] = mapped_column(Integer, nullable=False, comment="报告月份（1-12）")
+    status: Mapped[str] = mapped_column(
+        String(50), nullable=False, default="draft",
+        comment="状态：draft/submitted/ai_parsed/reviewed",
+    )
+    raw_content: Mapped[str | None] = mapped_column(Text, nullable=True, comment="原始内容")
+    structured_data: Mapped[dict | None] = mapped_column(JSONB, nullable=True, comment="结构化指标数据")
+    ai_summary: Mapped[str | None] = mapped_column(Text, nullable=True, comment="AI 生成的摘要")
+    ai_concerns: Mapped[dict | None] = mapped_column(JSONB, nullable=True, comment="AI 关注点列表")
+    submitted_by: Mapped[str | None] = mapped_column(String(36), ForeignKey("users.id"), nullable=True)
+    submitted_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True)
+    reviewed_by: Mapped[str | None] = mapped_column(String(36), ForeignKey("users.id"), nullable=True)
+    reviewed_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True)
+    created_at: Mapped[datetime] = mapped_column(
+        DateTime(timezone=True), default=lambda: datetime.now(timezone.utc)
+    )
+    updated_at: Mapped[datetime] = mapped_column(
+        DateTime(timezone=True),
+        default=lambda: datetime.now(timezone.utc),
+        onupdate=lambda: datetime.now(timezone.utc),
+    )