chore: publish from staged

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

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+# Phoenix Tracing: Custom Metadata (Python)
+
+Add custom attributes to spans for richer observability.
+
+## Install
+
+```bash
+pip install openinference-instrumentation
+```
+
+## Session
+
+```python
+from openinference.instrumentation import using_session
+
+with using_session(session_id="my-session-id"):
+    # Spans get: "session.id" = "my-session-id"
+    ...
+```
+
+## User
+
+```python
+from openinference.instrumentation import using_user
+
+with using_user("my-user-id"):
+    # Spans get: "user.id" = "my-user-id"
+    ...
+```
+
+## Metadata
+
+```python
+from openinference.instrumentation import using_metadata
+
+with using_metadata({"key": "value", "experiment_id": "exp_123"}):
+    # Spans get: "metadata" = '{"key": "value", "experiment_id": "exp_123"}'
+    ...
+```
+
+## Tags
+
+```python
+from openinference.instrumentation import using_tags
+
+with using_tags(["tag_1", "tag_2"]):
+    # Spans get: "tag.tags" = '["tag_1", "tag_2"]'
+    ...
+```
+
+## Combined (using_attributes)
+
+```python
+from openinference.instrumentation import using_attributes
+
+with using_attributes(
+    session_id="my-session-id",
+    user_id="my-user-id",
+    metadata={"environment": "production"},
+    tags=["prod", "v2"],
+    prompt_template="Answer: {question}",
+    prompt_template_version="v1.0",
+    prompt_template_variables={"question": "What is Phoenix?"},
+):
+    # All attributes applied to spans in this context
+    ...
+```
+
+## On a Single Span
+
+```python
+span.set_attribute("metadata", json.dumps({"key": "value"}))
+span.set_attribute("user.id", "user_123")
+span.set_attribute("session.id", "session_456")
+```
+
+## As Decorators
+
+All context managers can be used as decorators:
+
+```python
+@using_session(session_id="my-session-id")
+@using_user("my-user-id")
+@using_metadata({"env": "prod"})
+def my_function():
+    ...
+```