fix: variable name

[meelon-dev]

The README file refers the following variables:

• STATELESS_VALIDATOR_LOG_FILE_FILTER
• STATELESS_VALIDATOR_LOG_STDOUT_FILTER

However, further down in the same file, they are used as:

• STATELESS_VALIDATOR_LOG_FILE (without _FILTER)
• STATELESS_VALIDATOR_LOG_STDOUT (without _FILTER)

This file also uses:

• STATELESS_VALIDATOR_LOG_FILE (without _FILTER)
• STATELESS_VALIDATOR_LOG_STDOUT (without _FILTER)

Removed _FILTER from the variables, which does not break the code examples.

[Troublor]

Thanks for pointing out the discrepancy. We are refactoring the logging logic and will fix this along with the refactoring.

[flyq]

Thanks for the fix! Closing this as the inconsistency no longer exists on main: the whole STATELESS_VALIDATOR_LOG_* env-var family was renamed to the shared STATELESS_LOG_* prefix when logging was extracted into stateless-common (#74), and the legacy-name migration layer was removed in #127. The current README and code now consistently use STATELESS_LOG_FILE / STATELESS_LOG_STDOUT (see crates/stateless-common/src/logging.rs), so this patch no longer applies.