Fix export_index.py crash when using filenames without directories

[Copilot]

The export_index.py tool was crashing when provided with simple filenames instead of full directory paths. For example:

# This would crash with FileNotFoundError
python tools/export_index.py --json templates.json --csv templates.csv

# But this would work fine  
python tools/export_index.py --json output/templates.json --csv output/templates.csv

Root Cause
When a filename without directory separators is provided (like templates.json), os.path.dirname() returns an empty string. The code was then calling os.makedirs('') which fails with:

FileNotFoundError: [Errno 2] No such file or directory: ''

Solution
Modified both write_csv() and write_json() functions to only call os.makedirs() when the directory path is non-empty. This preserves the existing behavior for paths with directories while fixing the crash for simple filenames.

Changes

• Added directory path validation in write_csv() before calling os.makedirs()
• Added directory path validation in write_json() before calling os.makedirs()

Testing

• ✅ Simple filenames now work: templates.json, data.csv
• ✅ Directory paths still work: output/templates.json, data/export.csv
• ✅ Nested directories are created as before: nested/deep/path/file.json
• ✅ All existing functionality preserved
• ✅ Output format and content unchanged

This is a minimal, backward-compatible fix that makes the tool more user-friendly by supporting the most common use case of exporting to the current directory.

Original prompt

fix

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[Copilot]

Pull Request Overview

Fixes a crash in the export_index.py tool when using simple filenames without directory paths by adding validation before creating directories.

• Added directory path validation in write_csv() and write_json() functions
• Prevents os.makedirs('') calls that cause FileNotFoundError when using simple filenames
• Maintains backward compatibility for existing directory-based paths

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