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Add source tracking and improve error reporting in EDN parser

Add source tracking and improve error reporting in EDN parser: a task in LegoFlow-SWE (Harbor dataset). The EDN parser currently provides no way to determine where a parsed value came from in the original input. For example, after parsing nil or true , there is no API to retrieve the byte offsets…

The task

The EDN parser currently provides no way to determine where a parsed value came from in the original input. For example, after parsing `nil` or `true`, there is no API to retrieve the byte offsets of those tokens. Additionally, `nil` and boolean values are reused global singletons, making it impossible to attach…

Part of Lego-X/LegoFlow-SWE.