Initial implementation of mcq — document reading queue

Single-binary service: push raw markdown via REST/gRPC API, read rendered
HTML through mobile-friendly web UI. MCIAS auth on all endpoints, SQLite
storage, goldmark rendering with GFM and syntax highlighting.

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

internal/grpcserver/admin.go

@@ -0,0 +1,20 @@
+package grpcserver
+
+import (
+	"context"
+
+	pb "git.wntrmute.dev/mc/mcq/gen/mcq/v1"
+	"git.wntrmute.dev/mc/mcq/internal/db"
+)
+
+type adminService struct {
+	pb.UnimplementedAdminServiceServer
+	db *db.DB
+}
+
+func (s *adminService) Health(_ context.Context, _ *pb.HealthRequest) (*pb.HealthResponse, error) {
+	if err := s.db.Ping(); err != nil {
+		return &pb.HealthResponse{Status: "unhealthy"}, nil
+	}
+	return &pb.HealthResponse{Status: "ok"}, nil
+}