Adds a wire-efficiency regression guard the issue flagged as missing: correctness-only round-trip tests never asserted card type or wire cost, so the file-card-instead-of-cfile amplification #98 fixed could silently return. TestCloneServesCompressedNotExpandedContent serves a small compressible corpus, clones it over the real HTTP transport, and fails if the server emits any expanded file card or if served bytes exceed 3x the repository's stored size. Card type is the load-bearing signal: the reply container is compressed, so a raw-file-card regression on compressible content hides inside a byte ratio -- the 3x bound is only a coarse backstop.

Also adds a WIRE_MEASURE-gated manual harness that re-measures serve-side amplification against a real fossil client through a byte-counting proxy, with a fossil-serving-fossil control. Current main: 2.06x stored end to end (server response bodies alone are 1.04x, matching the fossil control's 1.03x), down from the 17.9x this issue reported. check-in: 1a73119ed4 user: [email protected] tags: trunk