lol-gateway: collapse to single-port + path routing via uapi_gnosis_set_handler

Previously the gateway bound three ports (7800 REST / 7801 gRPC / 7802 GraphQL),
each with its own accept loop (GnosisPortThread).  No current consumer fires more
than one protocol simultaneously, so this was unnecessary complexity.

New shape:
  uapi_gnosis_create(7800) + uapi_gnosis_set_handler(lolHandler) + uapi_gnosis_start

lolHandler is a C-ABI edge hook that path-dispatches on the parsed request:
  /api/v1/*              → REST handlers (lolRestDispatch)
  /lol.CorpusService/*   → gRPC-compat handlers (lolGrpcDispatch)
  /graphql               → GraphQL handler (lolGraphqlDispatch)
  else                   → 404

All handler business logic (corpus I/O, JSON encoding, GraphQL resolution,
gRPC-Web compat) is preserved unchanged.  The LOL_PORT env var still sets the
base port (default 7800); ports 7801/7802 are no longer bound.

Module-level g_data_dir / g_allocator / g_context_ready set before
uapi_gnosis_start; lolHandler reads them safely (gnosis background thread
starts after main() sets these).

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: hyperpolymath