MEM-030: serve_static leaks mmap on full conn ring (woof/CONN.c)

Now
DONE

serve_static maps the whole static asset via FILEMapRO and only releases it at :326 FILEUnMap. The intervening call(static_envelope) and call(u8bFeed) feed the file-sized body into the ~3MB conn out ring; u8bFeed returns BNOROOM when ring idle < body and PRO.h call() returns from serve_static before FILEUnMap, leaking one file-sized VMA plus fd per request. Repeatable and attacker-triggerable for any larger-than-ring static file, exhausting address space / fds. The goal is to never let a call() between map and unmap escape unmap on every path.

Issues

A fallible call() sits between FILEMapRO and FILEUnMap.

Blockers

None.

Planned

Unmap on every exit.