feat: Profile health score system (scoring engine, API, frontend)

Health scoring engine with 4 dimensions: Gateway stability (40%), config
completeness (25%), skill consistency (20%), and Cron success rate (15%).
Grades A(80-100) B(60-79) C(40-59) D(0-39) with detailed deduction items
and fix suggestions per dimension.

API endpoints:
  - GET /health/scores — list all profiles with grade filter + sort
  - GET /health/scores/{profile} — detail with deductions + suggestions
  - POST /health/compare — multi-profile config/skill comparison
  - POST /health/calculate — manual recalculation (owner only)

Frontend HealthPage: grade distribution cards, score table with expandable
detail rows, batch compare view with diff highlighting, grade/select/sort
filters, and owner-only recalculation.

Data sources use placeholders (TODO: hermes CLI / file reads) but the full
scoring logic is implemented end-to-end.

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

backend/app/main.py

@@ -4,7 +4,7 @@ from fastapi import FastAPI
 from fastapi.middleware.cors import CORSMiddleware
 
 from app.database import engine, Base
-from app.api import auth, users, audit, dashboard, gateway
+from app.api import auth, users, audit, dashboard, gateway, health
 from app.middleware.audit import AuditMiddleware
 
 
@@ -36,6 +36,7 @@ app.include_router(users.router)
 app.include_router(audit.router)
 app.include_router(dashboard.router, prefix="/api/v1")
 app.include_router(gateway.router, prefix="/api/v1")
+app.include_router(health.router, prefix="/api/v1")
 
 
 @app.get("/api/v1/health")