chore: bump version to 0.9.15, require uipath-platform>=0.1.18

Picks up x-uipath-traceparent-id trace context propagation from
uipath-platform 0.1.18 (UiPath/uipath-python#1535).

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: Clement Fauchere

pyproject.toml

@@ -1,13 +1,13 @@
 [project]
 name = "uipath-langchain"
-version = "0.9.14"
+version = "0.9.15"
 description = "Python SDK that enables developers to build and deploy LangGraph agents to the UiPath Cloud Platform"
 readme = { file = "README.md", content-type = "text/markdown" }
 requires-python = ">=3.11"
 dependencies = [
     "uipath>=2.10.29, <2.11.0",
     "uipath-core>=0.5.2, <0.6.0",
-    "uipath-platform>=0.1.12, <0.2.0",
+    "uipath-platform>=0.1.18, <0.2.0",
     "uipath-runtime>=0.10.0, <0.11.0",
     "langgraph>=1.0.0, <2.0.0",
     "langchain-core>=1.2.11, <2.0.0",
@@ -118,3 +118,6 @@ name = "testpypi"
 url = "https://test.pypi.org/simple/"
 publish-url = "https://test.pypi.org/legacy/"
 explicit = true
+
+[tool.uv.sources]
+uipath-platform = { path = "D:/source/uipath-python/packages/uipath-platform", editable = true }