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

internal/k8s/interface.go

@@ -0,0 +1,31 @@
+package k8s
+
+type JobStatus string
+
+const (
+	JobPending  JobStatus = "Pending"
+	JobRunning  JobStatus = "Running"
+	JobSucceeded JobStatus = "Succeeded"
+	JobFailed   JobStatus = "Failed"
+)
+
+type JobSpec struct {
+	Name          string
+	Namespace     string
+	Image         string
+	EnvVars       map[string]string
+	TimeoutSecond int
+}
+
+type Job struct {
+	Name      string
+	Namespace string
+	Status    JobStatus
+	Logs      string
+}
+
+type K8sClient interface {
+	CreateJob(spec *JobSpec) (*Job, error)
+	GetJob(name, namespace string) (*Job, error)
+	DeleteJob(name, namespace string) error
+}