build(workspace): add cloud platform member

openspec/changes/uv-workspace-packaging/tasks.md

@@ -4,7 +4,7 @@
   - Baseline: `uv run pytest -m "not integration"` -> 314 passed, 6 deselected.
   - Baseline: `uv build` -> root sdist and wheel built successfully.
 - [x] 1.2 Add `[tool.uv.workspace]` membership to the root project while retaining `device-agent-runtime` as the root package.
-- [ ] 1.3 Create `packages/cloud-platform/pyproject.toml` for the `device-cloud-platform` distribution with explicit build and package-discovery metadata.
+- [x] 1.3 Create `packages/cloud-platform/pyproject.toml` for the `device-cloud-platform` distribution with explicit build and package-discovery metadata.
 - [ ] 1.4 Declare `device-agent-runtime` as a workspace source dependency of `device-cloud-platform` without adding any reverse dependency.
 
 ## 2. Cloud Package Extraction

packages/cloud-platform/pyproject.toml

@@ -0,0 +1,14 @@
+[project]
+name = "device-cloud-platform"
+version = "0.1.0"
+description = "Cloud scheduling, device pooling, plugins, and SDK for Device Agent Runtime."
+requires-python = ">=3.14"
+dependencies = []
+
+[build-system]
+requires = ["setuptools>=69"]
+build-backend = "setuptools.build_meta"
+
+[tool.setuptools.packages.find]
+where = ["."]
+include = ["cloud*"]

pyproject.toml

@@ -24,7 +24,7 @@ dev = [
 ]
 
 [tool.uv.workspace]
-members = []
+members = ["packages/cloud-platform"]
 
 [tool.setuptools.packages.find]
 include = [