The console socket, proven in shadPS4 - no Steam Deck needed

User's insight: shadPS4 implements libSceNet over real host sockets, so obSCEne can serve the command protocol inside the emulator and a client connects from the host. That turns the networking from "needs a Deck" into "needs the emulator we already run in".

Done and demonstrated:

• net_target.c implemented against sceNet* (D107), signatures confirmed from OpenOrbis + shadPS4 both, moved out of the census into real platform.h declarations.
• SERVE=1 build flag; obscene_start runs the suite, announces net|listening|<port>, then serves in a reconnect loop.
• Built GEN=4 SERVE=1 (with the sweep exclusions - the serve loop is after the suite, so a known mid-suite crash must be excluded or it never listens), run in shadPS4, host port 9803 opened, connected from Windows, drove hello/report/bye. Transport reported scenet.
• verify: ok throughout.

Surprises

• The serving module has to carry the exclusion list. The first two runs died at 040-file/open-rejects-null before reaching the listen, exactly where the sweep says.
• sceNetSocket takes a name string as its first argument - confirmed by both sources, and the sort of arity detail that would have been a stack-corrupting guess under D008.