pcapstream-server is abandoned in favor of scpcap; drop the stale reference
in the doc's status line.
Add a footnote to §7.2 clarifying that the preallocating-writer hazard we
just spent significant effort diagnosing and fixing in scpcap's raw-.pcap
tailer doesn't apply to this document's .pcap.zst format: the compressed
writer only ever appends, and nothing that preallocates writes .pcap.zst
directly, so fstat-based phys/src tracking here remains sound as-is.
eric