chore: publish from staged

plugins/phoenix/skills/phoenix-tracing/references/projects-python.md

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+# Phoenix Tracing: Projects (Python)
+
+**Organize traces by application using projects (Phoenix's top-level grouping).**
+
+## Overview
+
+Projects group traces for a single application or experiment.
+
+**Use for:** Environments (dev/staging/prod), A/B testing, versioning
+
+## Setup
+
+### Environment Variable (Recommended)
+
+```bash
+export PHOENIX_PROJECT_NAME="my-app-prod"
+```
+
+```python
+import os
+os.environ["PHOENIX_PROJECT_NAME"] = "my-app-prod"
+from phoenix.otel import register
+register()  # Uses "my-app-prod"
+```
+
+### Code
+
+```python
+from phoenix.otel import register
+register(project_name="my-app-prod")
+```
+
+## Use Cases
+
+**Environments:**
+
+```python
+# Dev, staging, prod
+register(project_name="my-app-dev")
+register(project_name="my-app-staging")
+register(project_name="my-app-prod")
+```
+
+**A/B Testing:**
+
+```python
+# Compare models
+register(project_name="chatbot-gpt4")
+register(project_name="chatbot-claude")
+```
+
+**Versioning:**
+
+```python
+# Track versions
+register(project_name="my-app-v1")
+register(project_name="my-app-v2")
+```
+
+## Switching Projects (Python Notebooks Only)
+
+```python
+from openinference.instrumentation import dangerously_using_project
+from phoenix.otel import register
+
+register(project_name="my-app")
+
+# Switch temporarily for evals
+with dangerously_using_project("my-eval-project"):
+    run_evaluations()
+```
+
+**⚠️ Only use in notebooks/scripts, not production.**