v0.5.0

Release binaries, a one-line installer, and a waiver that no longer blocks.

Added

• Prebuilt release binaries and a curl | sh installer. Every v* tag
  publishes a statically linked x86_64-unknown-linux-musl archive with
  SHA256SUMS and an install.sh that resolves the latest release, verifies
  the checksum and installs to ~/.local/bin. The same tag publishes to
  crates.io, and CI builds the musl target on every push so the release path
  cannot rot.

Changed

• A config waiver is a gate the ladder leaves out, not a gate that blocks it.
  enabled = false on any gate runs nothing, still reports SKIPPED, and no
  longer stands in the way: the verdict is SHIP-READY and the exit code 0
  when every gate that ran passed, with the waiver named next to it — a waived: mutation — enabled = false in .mido.toml row under the verdict panel, a
  waived list in the --json verdict, and the same line in the markdown
  report's header. A green run with a waiver is never read as a green run
  without one. INCOMPLETE keeps exit code 2: a gate that could not run is
  never green.
• The mutation scope is the working tree against HEAD. A default run
  (in_diff = true) no longer hunts for a default branch: mido writes
  git diff HEAD — untracked sources included, the target scoped by a pathspec —
  and passes it as --in-diff. The sweep is the change at hand, never the
  commits a branch carries since origin/HEAD or master; a run with nothing
  uncommitted passes with "no rust file in the change" as its evidence.