[opentelemetry-instrumentation-google-genai] Add instrumentation for interactions.create and asyncinteractions.create methods

[DylanRussell]

Description

Initial PR to monkey patch and add instrumentation for the interactions API.

Reference documentation:

• https://ai.google.dev/gemini-api/docs/migrate-to-interactions
• https://ai.google.dev/api/interactions-api

Still TODO:

• Add tool definitions.
• Add interaction id somewhere (probably gen_ai.converastion.id)
• Expand input / output messages to capture all inputs / outputs -- the SDK accepts many different types here.

Unlike generate_content there is no GenerateContentConfig with lots of ways to tune the model, so most of the request attributes that are present in generate_content are missing here..

Type of change

• [ x] New feature (non-breaking change which adds functionality)

How has this been tested?

Unit tests

Checklist

• [ x] Followed the style guidelines of this project
• [ x] Changelog updated if the change requires an entry
• [ x] Unit tests added
• [ x] Documentation updated

[Copilot]

Pull request overview

Adds first-pass OpenTelemetry instrumentation for the Google GenAI SDK Interactions API (interactions.create and aio.interactions.create) within the opentelemetry-instrumentation-google-genai package, alongside a new unit-test suite for input/response parsing and basic span/attribute behavior.

Changes:

• Introduces src/opentelemetry/instrumentation/google_genai/interactions.py with sync/async monkey-patching and stream wrappers based on opentelemetry-util-genai.
• Adds a new tests/interactions/ suite covering parser behavior, sync/async calls, and basic streaming happy-path behavior.
• Updates instrumentation wiring in instrumentor.py, plus small docs/dev workflow updates and a changelog fragment.

Reviewed changes

Copilot reviewed 13 out of 13 changed files in this pull request and generated 8 comments.

Show a summary per file

File	Description
instrumentation/opentelemetry-instrumentation-google-genai/src/opentelemetry/instrumentation/google_genai/interactions.py	New interactions.create / aio.interactions.create instrumentation + stream wrappers and parsing helpers.
instrumentation/opentelemetry-instrumentation-google-genai/src/opentelemetry/instrumentation/google_genai/instrumentor.py	Wires the new interactions instrumentation into the main instrumentor lifecycle.
instrumentation/opentelemetry-instrumentation-google-genai/tests/interactions/base.py	Shared test base exercising sync/async interactions spans, attributes, and streaming happy path.
instrumentation/opentelemetry-instrumentation-google-genai/tests/interactions/test_interactions_sync.py	Sync interactions test runner implementation.
instrumentation/opentelemetry-instrumentation-google-genai/tests/interactions/test_interactions_async.py	Async interactions test runner implementation.
instrumentation/opentelemetry-instrumentation-google-genai/tests/interactions/test_parser.py	Unit tests for input/response-to-messages parsing helpers.
instrumentation/opentelemetry-instrumentation-google-genai/tests/interactions/util.py	Mock Interaction / SSE event helpers for the interactions tests.
instrumentation/opentelemetry-instrumentation-google-genai/tests/interactions/init.py	Test package marker.
instrumentation/opentelemetry-instrumentation-google-genai/README.rst	Minor usage text edit (needs update to mention interactions ops).
instrumentation/opentelemetry-instrumentation-google-genai/dev/pyproject.toml	Dev environment dependency/source tweaks (currently points to a personal fork).
instrumentation/opentelemetry-instrumentation-google-genai/dev/main.env	Dev env comment tweak for interactions API usage.
instrumentation/opentelemetry-instrumentation-google-genai/dev/call_instrumentation_lib_and_save_telemetry.py	Dev script edits (currently broken due to missing import).
instrumentation/opentelemetry-instrumentation-google-genai/.changelog/151.added	Towncrier fragment for the new interactions instrumentation.