fix: remove unused imports in monitoring/dashboard.py

Removed unused `json` and `evaluate_health` imports flagged by ruff.
Rebuilt vendor wheel.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: HanSur94

src/matlab_mcp/monitoring/dashboard.py

@@ -1,7 +1,6 @@
 """Dashboard Starlette sub-app with API routes and static file serving."""
 from __future__ import annotations
 
-import json
 from pathlib import Path
 from typing import Any
 
@@ -11,7 +10,6 @@
 from starlette.routing import Mount, Route
 from starlette.staticfiles import StaticFiles
 
-from matlab_mcp.monitoring.health import evaluate_health
 from matlab_mcp.monitoring.routes import (
     build_health_response,
     build_metrics_response,