* test: keep mini-allocated ports below the ephemeral floor
Allocated ports could land in 32768-55000, so a transient outbound dial
during mini startup (volume->master gRPC, etc.) could grab an allocated
port as its source port before the filer bound it, failing with
"bind: address already in use". Cap the range so port+GrpcPortOffset
stays under 32768.
* test: derive mini port cap from the ephemeral floor constant
Name the 32768 floor once and compute miniPortMax as floor-GrpcPortOffset
so the cap tracks the offset; reuse the constant in the regression test.
Random allocation could pick 33646 = admin.port (23646) + GrpcPortOffset.
weed mini reserves that as Admin's gRPC port even when the test only
overrides Master/Filer/S3/Iceberg, so the explicit Filer flag failed
with "reserved for gRPC calculation" and TestRisingWaveIcebergCatalog
flaked. Pre-seed the reserved set with every mini default HTTP port
plus its +10000 offset so a random pick (or its own gRPC offset) cannot
land on a service the caller left at its default.
AllocateMiniPorts(1) reserved masterPort and masterPort+GrpcPortOffset
by holding listeners open, but closed them on return. The subsequent
AllocatePorts call bound 127.0.0.1:0, so the OS could immediately reuse
the just-released mini gRPC port as a volume port — causing the volume
server to fail at bind time with "address already in use".
Introduce AllocatePortSet(miniCount, regularCount) that holds every
listener open until the full set is chosen, and route the five volume
test cluster builders through it.
Chris Lu