Feature: expose __version__ and top-level version() for server version Closes #623

[ravivarmanr26]

There's currently no clean way to check either the installed package version or the running Ollama server version from Python

Two small additions would fix this:

1. ollama.__version__ : the package version already exists internally, it just isn't exported. Exposing it follows standard Python packaging conventions and is a one-liner.
2. ollama.version() : a top-level wrapper around the existing Client.version() that hits /api/version. Async variant would be nice too.

Use case is things like this:

import ollama

print(ollama.__version__)          # "0.6.1"
print(ollama.version())            # "0.18.2"

if ollama.version() >= "0.3.0":
    # safe to use newer features
    pass

Useful for version-gated feature checks and CI/CD pipelines where you want to assert compatibility before running tests.