TokenFuse v0.4.3: binaries beside the images, and the trace says what it settled on

v0.4.3 (2026-09-02) is the first release that ships binaries beside the
images: tokenfuse for Linux and macOS on x86-64 and arm64, each with its
SHA256SUMS. The release workflow that #248 added on 2026-09-01 landed
after the v0.4.1 tag, and its first run on a tag, v0.4.2, failed on both
Linux targets at the musl step (#251 explains and fixes it), so v0.4.1 and
v0.4.2 have images and no assets, and this tag is the one that carries
them.

Two fixes in the gateway's money path:

• A response cut at the usage-parser cap (8 MiB) is settled on the
  pre-flight estimate, as before, and now says so: the parser reports the
  truncation, the settlement records its basis, the keys report counts
  truncated settlements since startup, and the trace row carries zero
  tokens beside the estimated cost so tokenfuse focus-export labels it
  estimated rather than settled (#249).
• The local Parquet trace reaches disk on a two-second tick and on SIGTERM
  as well as SIGINT, so an operator who makes ten calls and looks in
  TOKENFUSE_DATA_DIR sees them, and docker stop no longer loses the tail
  of the trace (#250).
• The binaries job of the release workflow now runs on a pull request that
  changes the workflow, with the image jobs held off there, so it is proven
  before a tag rather than by one (#251).

Nothing in the HTTP contract changed. Images: ghcr.io/taipanbox/tokenfuse:v0.4.3,
:cluster, and tokenfuse-control-plane:v0.4.3.