Add args parameter to REPLWrapper to support executable paths with spaces

[blink1073]

References

Replaces and closes #281.

Description

PR #281 by @tikuma-lsuhsc proposed adding an args parameter to REPLWrapper to allow passing additional arguments to the spawned command. This is needed to support executable paths containing spaces on Windows (e.g. an Octave installation in C:\Program Files\...).

This PR implements the same feature with the correct fix for the non-pty codepath.

Changes

• metakernel/replwrap.py: Added args: list[str] | None = None parameter to REPLWrapper.__init__; passed through to pexpect.spawnu.
• metakernel/pexpect.py: On the non-pty (Windows/PopenSpawn) path, skip shlex.split when args is explicitly provided — instead use [command] + args. This matches the pty_spawn behaviour and allows the command to be a literal executable path (with spaces) rather than a shell-split string.
• tests/test_replwrap.py: Added test_spawn_args test that starts a Python REPL with args=["-i", "-c", "x=4+7"] and verifies the result.
• tests/test_replwrap_init.py: Updated two mock assertions to expect the new args=None keyword argument in spawnu calls.

Backwards-incompatible changes

None. The new args parameter defaults to None and existing behaviour is unchanged when it is not supplied.

Testing

Existing test suite passes. New test_spawn_args test added to tests/test_replwrap.py.

AI usage

• This PR contains AI-generated content (Claude Sonnet 4.6 via Claude Code)

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 90.82%. Comparing base (7cc937b) to head (b4484f3).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #377   +/-   ##
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  Coverage   90.82%   90.82%           
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  Files          51       51           
  Lines        2943     2944    +1     
  Branches      410      411    +1     
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+ Hits         2673     2674    +1     
  Misses        190      190           
  Partials       80       80           

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