Where a configuration key's final value was observed to come from.
environment and file are the two sources the loader itself reads; each
value names its producer. unknown has exactly two producers: an opaque
injected IConfig instance, whose internals no observation can reach, and
a key present in the post-schema snapshot for which no environment or file
source was observed — it appeared only after schema parsing. unknown
never claims a mechanism, only the absence of an observed source.
Where a configuration key's final value was observed to come from.
environmentandfileare the two sources the loader itself reads; each value names its producer.unknownhas exactly two producers: an opaque injectedIConfiginstance, whose internals no observation can reach, and a key present in the post-schema snapshot for which no environment or file source was observed — it appeared only after schema parsing.unknownnever claims a mechanism, only the absence of an observed source.