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/noop.go

@@ -0,0 +1,27 @@
+package k8s
+
+type noopClient struct{}
+
+func NewNoopClient() K8sClient {
+	return &noopClient{}
+}
+
+func (c *noopClient) CreateJob(spec *JobSpec) (*Job, error) {
+	return &Job{
+		Name:      spec.Name,
+		Namespace: spec.Namespace,
+		Status:    JobPending,
+	}, nil
+}
+
+func (c *noopClient) GetJob(name, namespace string) (*Job, error) {
+	return &Job{
+		Name:      name,
+		Namespace: namespace,
+		Status:    JobPending,
+	}, nil
+}
+
+func (c *noopClient) DeleteJob(name, namespace string) error {
+	return nil
+}