Add project scaffolding with fx DI, SQLite migrations, and healthcheck

- go.mod with git.eeqj.de/sneak/chat module
- internal packages: globals, logger, config, db, healthcheck, middleware, handlers, server
- SQLite database with embedded migration system (schema_migrations tracking)
- Migration 001: schema_migrations table
- Migration 002: channels table
- Config with chat-specific vars (MAX_HISTORY, SESSION_TIMEOUT, MAX_MESSAGE_SIZE, MOTD, SERVER_NAME, FEDERATION_KEY)
- Healthcheck endpoint at /.well-known/healthcheck.json
- Makefile, .gitignore
- cmd/chatd/main.go entry point

internal/server/routes.go

@@ -0,0 +1,45 @@
+package server
+
+import (
+	"net/http"
+	"time"
+
+	sentryhttp "github.com/getsentry/sentry-go/http"
+	"github.com/go-chi/chi"
+	"github.com/go-chi/chi/middleware"
+	"github.com/prometheus/client_golang/prometheus/promhttp"
+	"github.com/spf13/viper"
+)
+
+func (s *Server) SetupRoutes() {
+	s.router = chi.NewRouter()
+
+	s.router.Use(middleware.Recoverer)
+	s.router.Use(middleware.RequestID)
+	s.router.Use(s.mw.Logging())
+
+	if viper.GetString("METRICS_USERNAME") != "" {
+		s.router.Use(s.mw.Metrics())
+	}
+
+	s.router.Use(s.mw.CORS())
+	s.router.Use(middleware.Timeout(60 * time.Second))
+
+	if s.sentryEnabled {
+		sentryHandler := sentryhttp.New(sentryhttp.Options{
+			Repanic: true,
+		})
+		s.router.Use(sentryHandler.Handle)
+	}
+
+	// Health check
+	s.router.Get("/.well-known/healthcheck.json", s.h.HandleHealthCheck())
+
+	// Protected metrics endpoint
+	if viper.GetString("METRICS_USERNAME") != "" {
+		s.router.Group(func(r chi.Router) {
+			r.Use(s.mw.MetricsAuth())
+			r.Get("/metrics", http.HandlerFunc(promhttp.Handler().ServeHTTP))
+		})
+	}
+}