feat: implement ntfy-discord bridge in Go

- SSE subscription to ntfy with auto-reconnect
- Discord webhook integration with embed formatting
- Priority to color mapping, tag to emoji conversion
- Native HashiCorp Vault support (Kubernetes + token auth)
- Hot reload secrets via fsnotify or Vault polling
- Prometheus metrics (/metrics endpoint)
- Health/ready endpoints for Kubernetes probes
- Comprehensive unit tests and fuzz tests
- Multi-stage Docker build (~10MB scratch image)
- CI/CD pipeline for Gitea Actions

main.go

@@ -0,0 +1,59 @@
+package main
+
+import (
+	"context"
+	"log/slog"
+	"os"
+	"os/signal"
+	"syscall"
+
+	"git.daviestechlabs.io/daviestechlabs/ntfy-discord/internal/bridge"
+	"git.daviestechlabs.io/daviestechlabs/ntfy-discord/internal/config"
+	"git.daviestechlabs.io/daviestechlabs/ntfy-discord/internal/server"
+)
+
+func main() {
+	// Setup structured logging
+	logLevel := slog.LevelInfo
+	if os.Getenv("LOG_LEVEL") == "debug" {
+		logLevel = slog.LevelDebug
+	}
+	logger := slog.New(slog.NewJSONHandler(os.Stdout, &slog.HandlerOptions{Level: logLevel}))
+	slog.SetDefault(logger)
+
+	slog.Info("starting ntfy-discord bridge")
+
+	// Create context with cancellation
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+
+	// Load configuration (may connect to Vault)
+	cfg, err := config.Load(ctx)
+	if err != nil {
+		slog.Error("failed to load config", "error", err)
+		os.Exit(1)
+	}
+	defer cfg.Close()
+
+	// Start the bridge
+	b := bridge.New(cfg)
+
+	// Start HTTP server for health/metrics
+	srv := server.New(cfg.HTTPPort, b)
+	go srv.Start()
+
+	// Start watching secrets for hot reload (Vault and/or file-based)
+	cfg.WatchSecrets(ctx)
+
+	// Start the bridge
+	go b.Run(ctx)
+
+	// Wait for shutdown signal
+	sigCh := make(chan os.Signal, 1)
+	signal.Notify(sigCh, syscall.SIGINT, syscall.SIGTERM)
+	<-sigCh
+
+	slog.Info("shutting down")
+	cancel()
+	srv.Shutdown(ctx)
+}