fix(config): add file_key auto-mapping to cfg_default

[helizaga]

Summary by CodeRabbit

• Bug Fixes
  • Improved consistency in configuration key mapping for gtr.* prefixed keys, ensuring they are properly resolved when used in configuration lookups.

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[coderabbitai]

Caution

Review failed

The pull request is closed.

Walkthrough

The cfg_default function in lib/config.sh now auto-maps file_key when the provided key starts with gtr. and file_key is empty by calling cfg_map_to_file_key, aligning its behavior with cfg_get_all so the corresponding .gtrconfig key is resolved earlier.

Changes

Cohort / File(s)	Summary
Config file_key auto-mapping lib/config.sh	Added conditional logic in cfg_default to call cfg_map_to_file_key and assign to file_key when the key starts with gtr. and file_key is empty, mirroring cfg_get_all (+5 lines)

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~10 minutes

Poem

🐇 I nudged a key that hid from sight,
Mapped gtr.* by moonlit light,
file_key woke and took its place,
Config smiles across the space,
Hooray—one less missing trace! 🎉

✨ Finishing touches

• 📝 Generate docstrings

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Post copyable unit tests in a comment
• Commit unit tests in branch fix/cfg-default-gtrconfig-mapping

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