When I channel a rune via an effect like Jhin Virtuoso, do these runes enter the board ready or exhausted?

Runes channeled via Jhin's Virtuoso ability enter the board ready.

Per FAQ #10639 and Rule 430.2, channeled runes default to the ready state unless the effect explicitly says "exhausted." Virtuoso says "channel 4 runes" with no such qualification, so they all come in ready. The same principle applies to any card effect that channels runes without specifying exhausted — ready is the default.