…architecture (vllm-project#32240)

Signed-off-by: chaunceyjiang <chaunceyjiang@gmail.com>

…architecture (vllm-project#32240)

Signed-off-by: chaunceyjiang <chaunceyjiang@gmail.com>

…architecture (vllm-project#32240)

Signed-off-by: chaunceyjiang <chaunceyjiang@gmail.com>
Signed-off-by: dsuhinin <suhinin.dmitriy@gmail.com>

…architecture (vllm-project#32240)

Signed-off-by: chaunceyjiang <chaunceyjiang@gmail.com>

- Branch OpenAI entrypoint imports on vllm version: vllm > 0.14.1 uses
  the reorganized paths introduced in vllm-project/vllm#32240
- Add ty: ignore[unresolved-import] suppressions for version-gated
  imports that may not exist in the installed vllm
- Matrix py-check CI job across vllm 0.14.1 and 0.15.1
- Fix is_reasoning_end signature: list[int] -> Sequence[int] to match
  the abstract base class

## Description

This PR aims to support vLLM v0.15.1 or newer verions.
To do this, we introduce a conditional import logic at the top of
`parser.py`


## Related Issue

<!--- Please link to the Github or Linear issue here -->

vllm-project/vllm#32240 introduces new
structure, which is a breaking change for melody

## Motivation and Context

<!--- Why is this change required? What problem does it solve? -->

Melody does not support vLLM v0.15 or newer verions.

## How Has This Been Tested?

<!--- Please describe how you tested your changes -->
<!--- Add new tests to validate the functionality if possible -->

### Check1: Confirm that import works with both vLLM versions

```
$ uv pip list | grep vllm
vllm                              0.15.1
$ uv run cohere_melody_vllm/parser.py
# no error
```

```
$ uv pip list | grep vllm
vllm                              0.14.1
$ uv run cohere_melody_vllm/parser.py
# no error
```


### Check2: Tool Calling works with vLLM v0.15.1

Start server

```
uv run vllm serve CohereLabs/c4ai-command-r7b-12-2024 --reasoning-parser cohere2 --reasoning-parser-plugin ./cohere_melody_vllm/parser.py --tool-parser-plugin ./cohere_melody_vllm/parser.py --tool-call-parser cohere2 --enable-auto-tool-choice
```

and then send a tool calling query

```
$ uv run tool.py
ChatCompletion(id='chatcmpl-a8a2b2e52a4dc558', choices=[Choice(finish_reason='tool_calls', index=0, logprobs=None, message=ChatCompletionMessage(content=None, refusal=None, role='assistant', annotations=None, audio=None, function_call=None, tool_calls=[ChatCompletionMessageFunctionToolCall(id='chatcmpl-tool-a9f3c1ba457d277f', function=Function(arguments='{"location": "San Francisco, California", "unit": "celsius"}', name='get_weather'), type='function')], reasoning='I will use the get_weather tool to find out the weather in San Francisco, California in Celsius.', reasoning_content='I will use the get_weather tool to find out the weather in San Francisco, California in Celsius.'), stop_reason=None, token_ids=None)], created=1776133545, model='CohereLabs/c4ai-command-r7b-12-2024', object='chat.completion', service_tier=None, system_fingerprint=None, usage=CompletionUsage(completion_tokens=69, prompt_tokens=1302, total_tokens=1371, completion_tokens_details=None, prompt_tokens_details=None), prompt_logprobs=None, prompt_token_ids=None, kv_transfer_params=None)
'Function called: get_weather'
'Arguments: {"location": "San Francisco, California", "unit": "celsius"}'
'Result: Getting the weather for San Francisco, California in celsius...'
```

<!-- CURSOR_SUMMARY -->
---

> [!NOTE]
> **Medium Risk**
> Adds version-dependent imports for vLLM OpenAI protocol types, so a
mistake in version detection or module paths could cause runtime import
failures across supported vLLM versions.
> 
> **Overview**
> Adds vLLM version-aware import logic in `cohere_melody_vllm/parser.py`
to handle the OpenAI entrypoint protocol module reorganization
introduced after vLLM `0.14.1`, enabling the plugin to run against both
old and new layouts.
> 
> Updates the Python bindings CI `py-check` job to run `ty check` in a
matrix against vLLM `0.14.1` and `0.15.1` to continuously validate
compatibility.
> 
> <sup>Reviewed by [Cursor Bugbot](https://cursor.com/bugbot) for commit
e3aa4f8. Bugbot is set up for automated
code reviews on this repo. Configure
[here](https://www.cursor.com/dashboard/bugbot).</sup>
<!-- /CURSOR_SUMMARY -->