MSG_MHF_GET_EXTRA_INFO (0xA6) and MSG_MHF_GET_COG_INFO (0xC3) had
Parse() returning NOT IMPLEMENTED. The dispatch loop treats any Parse
error as a hard drop — no ACK is ever sent, so the client waits
indefinitely and effectively soft-locks when entering the G-rank
Workshop or Master Felyne (Cog) screens.
Fix: parse AckHandle (the only field we can confirm from the protocol)
and respond with doAckBufFail so the client receives a well-formed
buf-type ACK with error code 1. The client's fail branch for these
requests exits cleanly without reading response fields, avoiding the
read-past-EOF crash that an empty success ACK would cause.
The full response format for both packets is still unknown; a complete
implementation requires further RE. The TODO comments mark the gap.
Fixes#180.
Port test files from v9.2.x-stable branch to increase channelserver
coverage from 13.8% to 25.6% (556 tests passing).
Adapted all files to main's struct definitions: config import alias,
Airou/CatDefinition rename, packet field mismatches, Raviente struct
differences, and maxPlayers defaults. Removed tests referencing
production code not yet on main (Player, FestivalColour, etc.).
Excluded handlers_register_test.go (Raviente completely redesigned).
