- Add transactionId and messageId as camelCase aliases in model.go contextKeys map,
pointing to the same ContextKeyTxnID and ContextKeyMsgID constants. This allows
adapter configs to reference either form without failing startup validation.
- In reqpreprocessor, add firstNonNil() helper for subscriber/caller ID lookups
so bap_id/bapId and bpp_id/bppId are both resolved correctly regardless of
which beckn spec version the payload uses. snake_case takes precedence when both
are present.
- Add snakeToCamel() helper used in the context key loop so a single config entry
(e.g. transaction_id) automatically also checks the camelCase form (transactionId)
without requiring any config file changes.
- Add TestSnakeToCamel, TestCamelCaseSubscriberID, TestCamelCaseContextKeys to
cover all new code paths.
Fixes#637
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>