Resolved compilation challenges around SerialisedHeader in the immdb-client: the type lacks HasHeader and Show instances, requiring workarounds to use it as chain state in the chain sync client (commit a12ff9b).
Added informative chain sync message tracing for both client and server components in immdb-server/immdb-client, using showTracing for human-readable protocol message logs (commit 7004e36, commit c5f1f3f).
Required the HasNestedContent constraint on blk for clientChainSync to enable the more informative tracer (commit 0ec200f).
