feat: implement proto-gen platform

- Config loader with env var expansion and validation
- SQLite database with tasks and toolchain_versions tables
- Gitea REST API client for repository and branch operations
- K8s client for Job lifecycle management (with noop fallback for local dev)
- REST API: tasks CRUD, retry, plugins, version management
- Worker/scheduler with polling, concurrency control, and job tracking
- Static frontend: generate, tasks, settings pages
- Toolchain images: Go and Node.js Dockerfiles with entrypoint scripts
- Helm chart with deployment, service, configmap, ingress, PVC
- Multi-stage Dockerfile for service
- Unit tests for config, database, gitclient, k8s, api, worker
- E2E tests for idempotency, version switch, failure recovery

cmd/server/main.go

@@ -0,0 +1,78 @@
+package main
+
+import (
+	"context"
+	"flag"
+	"log"
+	"net/http"
+	"os"
+	"os/signal"
+	"syscall"
+
+	"proto-gen/internal/api"
+	"proto-gen/internal/config"
+	"proto-gen/internal/database"
+	"proto-gen/internal/gitclient"
+	"proto-gen/internal/k8s"
+	"proto-gen/internal/worker"
+)
+
+func main() {
+	configPath := flag.String("config", "config.yaml", "path to config file")
+	flag.Parse()
+
+	cfg, err := config.Load(*configPath)
+	if err != nil {
+		log.Fatalf("loading config: %v", err)
+	}
+
+	db, err := database.New("proto-gen.db")
+	if err != nil {
+		log.Fatalf("initializing database: %v", err)
+	}
+	defer db.Close()
+
+	git := gitclient.NewClient(cfg.Git.BaseURL, cfg.Git.Token)
+
+	var k8sClient k8s.K8sClient
+	if cfg.Cluster.Kubeconfig == "" || cfg.Cluster.Kubeconfig == "/dev/null" {
+		log.Println("no kubeconfig provided, running in local mode (no K8s jobs)")
+		k8sClient = k8s.NewNoopClient()
+	} else {
+		k8sClient, err = k8s.NewClient(cfg.Cluster.Kubeconfig)
+		if err != nil {
+			log.Printf("warning: k8s client init failed: %v, running in local mode", err)
+			k8sClient = k8s.NewNoopClient()
+		}
+	}
+
+	scheduler := worker.NewScheduler(db, k8sClient, cfg)
+
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+
+	go scheduler.Start(ctx)
+
+	server := api.NewServer(db, cfg, git)
+
+	httpServer := &http.Server{
+		Addr:    cfg.Server.Addr,
+		Handler: server,
+	}
+
+	go func() {
+		if err := httpServer.ListenAndServe(); err != nil && err != http.ErrServerClosed {
+			log.Fatalf("server error: %v", err)
+		}
+	}()
+
+	log.Printf("proto-gen server started on %s", cfg.Server.Addr)
+
+	quit := make(chan os.Signal, 1)
+	signal.Notify(quit, syscall.SIGINT, syscall.SIGTERM)
+	<-quit
+
+	log.Println("shutting down...")
+	cancel()
+	httpServer.Shutdown(context.Background())
+}