fix: preserve Ollama streaming tool calls

[andreivince]

Closes #1922.

Ollama can emit tool_calls before the final done=true chunk when streaming. The adapter was only reading chunk.message.tool_calls from the final chunk, so a real streamed tool call could turn into an empty final ADK response.

I changed the streaming path to accumulate tool calls across chunks, then include them when building the final LlmResponse. I also moved the Ollama tool-call to ADK part conversion into one helper so streaming and non-streaming stay consistent.

I verified this two ways:

• Added a regression test where the tool call arrives on a non-final chunk and the done chunk has no tool calls. This failed before the fix and passes after it.
• Reproduced against a live local Ollama server with qwen3:0.6b. Raw Ollama emitted get_temperature({"city": "Tokyo"}) on done=false, then a final done=true chunk with no tool calls. Before the fix, kagent returned function_calls=0; after the fix, kagent returned the expected get_temperature function call.

Checks run:

• uv run pytest packages/kagent-adk/tests/unittests/models/test_ollama.py -q
• uv run pytest packages/kagent-adk/tests/unittests/models --ignore=packages/kagent-adk/tests/unittests/models/test_tls_e2e.py -q
• uv run ruff check packages/kagent-adk/src/kagent/adk/models/_ollama.py packages/kagent-adk/tests/unittests/models/test_ollama.py

One note: the full model test directory has unrelated local TLS E2E failures because the cert fixture files are missing in my checkout. The non-TLS model tests passed.

[Copilot]

Pull request overview

Note

Copilot was unable to run its full agentic suite in this review.

Fixes a bug in the Ollama streaming path where tool calls emitted in non-final chunks were dropped because only the final (done) chunk's tool_calls were inspected. Now tool calls are accumulated across all streamed chunks before being added to the final response.

Changes:

• Extract the tool-call → types.Part conversion into a helper _convert_tool_call_to_part.
• Accumulate tool_calls across all streamed chunks and append them on the done chunk.
• Add a unit test covering tool-call accumulation when the tool call arrives before the done chunk.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
python/packages/kagent-adk/src/kagent/adk/models/_ollama.py	Refactors tool-call conversion into a helper and fixes streaming to aggregate tool calls across chunks.
python/packages/kagent-adk/tests/unittests/models/test_ollama.py	Adds a streaming test verifying tool calls from earlier chunks are included in the final response.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[EItanya]

Thanks so much for the contribution, you will need to sign your commits to pass DCO before we can merge

[jmhbh]

lgtm after commits are signed.

[andreivince]

Thanks @EItanya, signed the commit and force-pushed the clean branch. @jmhbh DCO is green now too.

[andreivince]

Looks like the remaining build (app) failure is a CI flake. It fails in the arm64 Docker base layer with a QEMU illegal-instruction error before kagent source is copied in.

This PR only touches the Ollama adapter and its unit test, and the Python lint/tests are green. Could someone rerun the failed build jobs?