feat(M0): 工程地基 - Go API + Python 采集骨架 + CI + 数据契约

- api/: Go(chi) 只读 API 骨架, /healthz + 版本化路由(占位), Dockerfile, 单测
- ingestion/: Python 采集/ETL 包骨架, units 单位归一化(纯函数+测试), adapter 协议
- docker-compose.yml: postgres + redis + minio + api
- .github/workflows/ci.yml: Go build/vet/test + Python ruff/pytest
- docs/data-contract.md(两端共享契约) + docs/disclaimer.md(不提供购买声明)
- migrations/ 占位(M1 起填充)

Co-Authored-By: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>

api/Dockerfile

@@ -0,0 +1,13 @@
+# Build stage
+FROM golang:1.23-alpine AS build
+WORKDIR /src
+COPY go.mod go.sum ./
+RUN go mod download
+COPY . .
+RUN CGO_ENABLED=0 go build -o /out/server ./cmd/server
+
+# Runtime stage
+FROM gcr.io/distroless/static-debian12
+COPY --from=build /out/server /server
+EXPOSE 8080
+ENTRYPOINT ["/server"]