Improved Configuration Logic

[lilalinda]

Implement a default configuration in TOML and command line or input file overrides (such as log level or QLOG path for storing files).

Clarify QUIC-LY transport parameter semantics and maintain own + peer settings separately (where useful). For example, max_ack_delay could be asymmetric.

[lilalinda]

Last bits: honor log level for console output and allow for file logging (QLOG format later).