packaging: build recipes for arch, gentoo, nix, void, fedora

Five distro recipes in packaging/, all following the same recipe:
unpack the Gitea release archive (which extracts to fastwc/), run
autoreconf -fi (the generated configure/Makefile.in are not committed),
configure, make, make install - the binary needs only glibc.

Each recipe notes the release prerequisite: the archive URL requires a
v0.1.0 tag on the remote, and Arch/Nix/Void carry an integrity
placeholder to fill in once the tag exists. The PKGBUILD was validated
with makepkg --printsrcinfo, and the full build recipe was run
end-to-end from a Gitea-layout tarball (autoreconf, configure, make,
make install DESTDIR) producing a working /usr/bin/fastwc.

packaging/gentoo/app-misc/fastwc/fastwc-0.1.0.ebuild

@@ -0,0 +1,29 @@
+# Copyright 1999-2026 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=8
+
+inherit autotools
+
+DESCRIPTION="A wc replacement that beats GNU wc - SIMD kernels, mmap, threads"
+HOMEPAGE="https://git.spectoria.dev/huntedbytheirs/fastwc"
+# requires a v0.1.0 tag on the Gitea remote
+SRC_URI="https://git.spectoria.dev/huntedbytheirs/fastwc/archive/v${PV}.tar.gz"
+
+LICENSE="MIT"
+SLOT="0"
+KEYWORDS="~amd64"
+
+# Gitea archives extract to a directory named after the repo
+S="${WORKDIR}/fastwc"
+
+BDEPEND="
+	>=sys-devel/autoconf-2.69
+	sys-devel/automake
+	sys-devel/libtool
+"
+
+src_prepare() {
+	default
+	eautoreconf
+}