[Feature] Add GitHub Action Workflow for Arch Linux AUR Package publishing (#33)

* Feature: add GitHub Actions workflow for publishing Arch Linux AUR package

* Fix issues in Arch Linux AUR publishing process

* Add patch to fix default Arch Linux binary path location issues

* fix: PKGBUILD compatibility with numa v0.10.1, fix QEMU action SHA pin

Three small bug fixes that make this PR mergeable end-to-end against
current main, without changing the package design (still numa-git,
still pushed on every main commit, still tracking HEAD via pkgver()):

1. Simplified prepare() — drop the obsolete sed patching for
   /usr/local/bin/numa. That literal only appears in a comment
   in current main; the actual binary path is determined at
   runtime via std::env::current_exe(). Additionally, numa
   v0.10.1 ships PR #43 which makes numa FHS-compliant on Linux
   out of the box (/var/lib/numa for data dir), so no source
   patching is needed at all on Arch.

2. Fixed package() sed for the systemd unit. The previous sed
   targeted "ExecStart=/usr/local/bin/numa" but numa.service
   actually uses "{{exe_path}}" as a templating placeholder
   that's substituted at runtime by replace_exe_path() when
   `numa install` runs. The sed silently did nothing, and the
   AUR-installed unit file would have a literal "{{exe_path}}"
   that systemd cannot start. Fixed sed:

     sed 's|{{exe_path}}|/usr/bin/numa /etc/numa.toml|g' \
       numa.service > numa.service.patched

3. Fixed broken docker/setup-qemu-action SHA pin in
   publish-aur.yml. The pinned SHA
   6882732593b27c7f95a044d559b586a46371a68e doesn't exist as
   a commit in upstream docker/setup-qemu-action. Verified
   v3.0.0 SHA is 68827325e0b33c7199eb31dd4e31fbe9023e06e3.
   Without this fix the aarch64 validate job would fail to
   load the action at workflow start.

Also refreshed the stale pkgver placeholder in PKGBUILD and
.SRCINFO from 0.9.1.r0.g1234abc to 0.10.1.r0.g0000000 — purely
cosmetic since pkgver() auto-overrides on every makepkg run,
but at least the in-VC value reflects the current era.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* fix: make AUR packaging x86_64-only and stabilize local validation

Turns out Arch Linux doesn't officially support aarch64 architecture, so we will drop if from this AUR build process.

Changes:

- drop aarch64 from PKGBUILD, .SRCINFO, and AUR validation workflow
- keep AUR process aligned with official Arch Linux x86_64 support
- install rust directly in CI to avoid Arch cargo provider prompts
- fetch sources before running cargo audit and audit inside the
fetched repo
- disable makepkg LTO for this package to avoid Arch packaging link
failures
- mark /etc/numa.toml as a backup file
- Add local AUR build scratch directory exclusion to .gitignore

* Add temporary AUR test workflow

* Update github actions checkout workflow version

* remove temporary AUR test workflow

* fix: correct AUR SSH host key fingerprint

The previously pinned ed25519 key was truncated (52 chars) and did not
match the actual aur.archlinux.org host key. Verified via ssh-keyscan.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

---------

Co-authored-by: Razvan Dimescu <ssaricu@gmail.com>
Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

PKGBUILD

@@ -0,0 +1,62 @@
+# Maintainer: razvandimescu <razvan@dimescu.com>
+pkgname=numa-git
+_pkgname=numa
+pkgver=0.10.1.r0.g0000000 # Placeholder — pkgver() rewrites this on each makepkg run
+pkgrel=1
+pkgdesc="Portable DNS resolver in Rust — .numa local domains, ad blocking, developer overrides, DNS-over-HTTPS"
+arch=('x86_64')
+url="https://github.com/razvandimescu/numa"
+license=('MIT')
+options=('!lto')
+depends=('gcc-libs' 'glibc')
+makedepends=('cargo' 'git')
+provides=("$_pkgname")
+conflicts=("$_pkgname")
+backup=('etc/numa.toml')
+source=("$_pkgname::git+$url.git")
+sha256sums=('SKIP')
+
+pkgver() {
+  cd "$srcdir/$_pkgname"
+  ( set -o pipefail
+    git describe --long --tags 2>/dev/null | sed 's/\([^-]*-g\)/r\1/;s/-/./g' ||
+    printf "r%s.%s" "$(git rev-list --count HEAD)" "$(git rev-parse --short HEAD)"
+  ) | sed 's/^v//'
+}
+
+prepare() {
+  cd "$srcdir/$_pkgname"
+  # numa v0.10.1+ uses FHS-compliant paths on Linux by default
+  # (/var/lib/numa for data, journalctl for logs), so no source
+  # patching is needed. The earlier sed targeted /usr/local/bin/numa,
+  # which only appears in a comment in current main.
+  export RUSTUP_TOOLCHAIN=stable
+  cargo fetch --locked
+}
+
+build() {
+  cd "$srcdir/$_pkgname"
+  export RUSTUP_TOOLCHAIN=stable
+  cargo build --frozen --release
+}
+
+check() {
+  cd "$srcdir/$_pkgname"
+  export RUSTUP_TOOLCHAIN=stable
+  cargo test --frozen
+}
+
+package() {
+  cd "$srcdir/$_pkgname"
+  install -Dm755 "target/release/$_pkgname" "$pkgdir/usr/bin/$_pkgname"
+
+  # numa.service uses {{exe_path}} as a placeholder substituted by
+  # `numa install` at runtime via replace_exe_path(). For an AUR
+  # package install (no `numa install` step), we substitute it
+  # statically here so systemd gets a real ExecStart path.
+  sed 's|{{exe_path}}|/usr/bin/numa /etc/numa.toml|g' numa.service > numa.service.patched
+  install -Dm644 "numa.service.patched" "$pkgdir/usr/lib/systemd/system/numa.service"
+
+  install -Dm644 "numa.toml" "$pkgdir/etc/numa.toml"
+  install -Dm644 "LICENSE" "$pkgdir/usr/share/licenses/$pkgname/LICENSE"
+}