feat: T1.4 健康度仪表盘 — 后端聚合 API + 前端驾驶舱

- 后端：dashboard 路由（summary 聚合 + scores 列表）
- 前端：驾驶舱首页（KPI 卡片 + 健康度概览）
- 测试：4 个仪表盘测试（总计 37 tests passed）
- 前端构建 12 路由成功

backend/app/schemas/health_score.py

@@ -0,0 +1,30 @@
+"""健康度评分相关 Pydantic schema。"""
+
+from datetime import datetime
+from pydantic import BaseModel
+
+
+class HealthScoreResponse(BaseModel):
+    """健康度评分响应。"""
+
+    id: str
+    company_id: str
+    total_score: float
+    financial_score: float | None = None
+    operational_score: float | None = None
+    ai_commercial_score: float | None = None
+    ai_cost_score: float | None = None
+    trend: str | None = None
+    evidence_json: dict | None = None
+    recommendations_json: dict | None = None
+    calculated_at: datetime
+
+
+class DashboardSummary(BaseModel):
+    """仪表盘汇总数据。"""
+
+    total_companies: int
+    avg_health_score: float
+    high_risk_count: int
+    pending_reports: int
+    recent_scores: list[HealthScoreResponse]