feat: add Timeweb Cloud provider for Woodpecker CI autoscaler

- Implement timewebcloud provider with DeployAgent, RemoveAgent, ListDeployedAgentNames
- Add minimal HTTP API client for Timeweb Cloud (create/list/delete servers)
- Register provider in main.go with CLI flags
- Add timeweb-list and timeweb-tester utilities
- Include Dockerfile and docker-compose.yml for deployment
- Update DEPLOY.md with verified OS/preset IDs

engine/types/provider.go

@@ -0,0 +1,13 @@
+package types
+
+import (
+	"context"
+
+	"go.woodpecker-ci.org/woodpecker/v3/woodpecker-go/woodpecker"
+)
+
+type Provider interface {
+	DeployAgent(context.Context, *woodpecker.Agent) error
+	RemoveAgent(context.Context, *woodpecker.Agent) error
+	ListDeployedAgentNames(context.Context) ([]string, error)
+}