`mlugg/setup-zig@v1` is deprecated and only knows the pre-0.14
tarball name (`zig-linux-x86_64-<ver>.tar.xz`), so every mirror —
and the official ziglang.org/builds — returned 404 for Zig 0.15.2
on both the v0.0.1 and v0.0.2 release runs. v2 uses the new
`zig-x86_64-linux-<ver>.tar.xz` layout that Zig switched to in
0.14+.
Also rolls the existing CHANGELOG `[Unreleased]` work into a
dated `[0.0.3]` section and adds the CI fix to its Fixed list.
Switches CLI flag parsing from Go's stdlib `flag` to spf13/pflag so
`--project` (and the internal `--socket` / `--identity` / `--scenario`
flags) are the only accepted form; single-hyphen long flags like
`-project` are now rejected. Help output renders the canonical `--`
form.
Adds `patterm --version`, which prints the build version, short commit,
and build date (e.g. `patterm v0.0.1 (commit abc1234, built 2026-05-14)`).
The version string is injected at build time — `make patterm` derives it
from `git describe --tags --always --dirty`, and the release workflow
injects the pushed tag. Commit/date come from the Go toolchain's
embedded VCS info via `runtime/debug.ReadBuildInfo`, so no manual
bumping is required.