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

docker/Dockerfile

@@ -0,0 +1,18 @@
+FROM --platform=$BUILDPLATFORM golang:1.26 AS build
+
+WORKDIR /src
+COPY . .
+ARG TARGETOS TARGETARCH
+RUN --mount=type=cache,target=/root/.cache/go-build \
+    --mount=type=cache,target=/go/pkg \
+    make build
+
+FROM --platform=$BUILDPLATFORM scratch
+ENV GODEBUG=netdns=go
+
+# copy certs from build image
+COPY --from=build /etc/ssl/certs/ca-certificates.crt /etc/ssl/certs/ca-certificates.crt
+# copy agent binary
+COPY --from=build /src/dist/woodpecker-autoscaler /bin/
+
+ENTRYPOINT ["/bin/woodpecker-autoscaler"]