refactor: eliminate duplicate import_concoredocker.m logic and fix Windows-only batch generation (fixes #285)

[GaneshPatil7517]

Hi @pradeeban Sir
This PR resolves Issue #285 by removing duplication between import_concore.m and import_concoredocker.m, and addresses Copilot review feedback on file descriptor leaks and error handling.

Changes Made

• import_concore.m: Wrapped concorekill.bat generation in an ispc guard so it only executes on Windows
• import_concore.m: Added fopen return value check (~= -1) before writing concorekill.bat, with a graceful warning on failure
• import_concore.m: Added proper fclose for concore.iport and concore.oport file descriptors in both success and error paths
• import_concoredocker.m: Removed concorekill.bat generation entirely (Docker containers always run Linux)
• import_concoredocker.m: Replaced try/catch with fopen return value check and guaranteed fclose for concore.iport / concore.oport

Behavior

Environment	concorekill.bat created?
Windows (non-Docker)	Yes
Linux (non-Docker)	No
Docker (Linux)	No

Scope

• Limited to import_concore.m and import_concoredocker.m
• No changes to path detection logic
• No changes to Verilog, Python, or other language files
• No functional changes for Windows users

Testing

• All 77 existing tests pass
• Verified Windows batch file is generated only when ispc is true
• Verified Docker variant contains no .bat generation code
• File descriptors are now properly closed on all code paths

[Copilot]

Pull request overview

This PR addresses issue #285 by preventing Windows-only concorekill.bat generation in non-Windows environments, especially for Docker-generated (Linux) builds of the MATLAB/Octave runtime helpers.

Changes:

• Wrapped concorekill.bat generation in import_concore.m with an ispc guard so it only runs on Windows.
• Removed concorekill.bat generation from import_concoredocker.m (Docker/Linux template).

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 3 comments.

File	Description
import_concore.m	Generates concorekill.bat only on Windows via ispc guard; rest of initialization unchanged.
import_concoredocker.m	Removes Windows batch generation from the Docker template while keeping the same init logic.

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[pradeeban]

/gemini-review