fix: validate duplicate language configurations in CHECKCFG#1376

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joaodinissf:fix/checkcfg-duplicate-language-validation

Commits on Jun 12, 2026

fix: validate and quick-fix duplicate languages in CHECKCFG

joaodinissf
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claude
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Commits on Jun 13, 2026

test: cover the duplicate-language merge as a UI-independent core operation

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claude
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Commits on Jun 14, 2026

docs: document the order-preserving merge contract (response to review)

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claude
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fix: drop the merge quick-fix, keep only duplicate-language validation

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claude
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