Fix default execution type in CLI and add test for run command

[Titas-Ghosh]

Hi @pradeeban ,This pr fixes issue #260

Why this change?

concore run defaults to --type windows on all platforms. On Linux/macOS this generates Windows scripts (.bat) and Windows commands, so the default Quick Start fails unless users override --type posix.

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What was the problem?

• CLI default is always windows
• Non‑Windows users get Windows scripts by default
• Default behavior is wrong on Linux/macOS

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How I solved it

1. Made the default --type OS-aware (windows on Windows, posix otherwise)
2. Added a regression test to verify the generated build script matches the platform default

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Changes / Implementation

• concore_cli/cli.py
  • Dynamic default for --type
• tests/test_cli.py
  • New test test_run_command_default_type

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How to Test Locally

python -m pytest -v tests/test_cli.py
python -m pytest -v

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Evidence

• python -m pytest -v
57 passed in 2.41s

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PR Checklist

• Added tests for the new behavior
• Ran full test suite locally
• No public API changes
• Backwards-compatible (Windows default unchanged)