Add Go module, fail-fast config loader and /health endpoint

- go.mod: module code.cubecraftlabs.com/Maniacs_Mansion/Meal-Quest, go 1.25,
  sole dependency github.com/go-chi/chi/v5.
- internal/config: Load() reads MEALQUEST_* env vars and *_FILE secrets,
  collects every missing/invalid value into one error naming each variable,
  rejects inline secrets, and redacts secrets when formatted.
- internal/server: chi router serving GET /health -> {"status":"ok","version"}.
- cmd/server: wiring only; slog JSON logging, version via -ldflags
  "-X main.version=...", graceful shutdown on SIGINT/SIGTERM.
- .gitignore: cover .env*, deploy/secrets/, node_modules, dist, *.db.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

internal/server/server.go

@@ -0,0 +1,37 @@
+// Package server builds the MealQuest HTTP router.
+package server
+
+import (
+	"encoding/json"
+	"log/slog"
+	"net/http"
+
+	"github.com/go-chi/chi/v5"
+)
+
+// NewRouter returns the HTTP handler for the service. version is reported by
+// GET /health.
+func NewRouter(logger *slog.Logger, version string) http.Handler {
+	r := chi.NewRouter()
+	r.Get("/health", health(logger, version))
+	return r
+}
+
+type healthResponse struct {
+	Status  string `json:"status"`
+	Version string `json:"version"`
+}
+
+func health(logger *slog.Logger, version string) http.HandlerFunc {
+	body, err := json.Marshal(healthResponse{Status: "ok", Version: version})
+	if err != nil {
+		panic(err) // two string fields cannot fail to marshal
+	}
+	return func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "application/json")
+		w.WriteHeader(http.StatusOK)
+		if _, err := w.Write(body); err != nil {
+			logger.WarnContext(r.Context(), "write health response", "error", err)
+		}
+	}
+}