fix: add cmake to PKGBUILD makedepends

aws-lc-sys (vendored TLS dependency) shells out to cmake at build
time to compile AWS-LC's C sources. cmake isn't part of Arch's
base-devel group, so a clean build host with only base-devel, cargo,
and git installed would fail partway through cargo build.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_013XCcBkpdbUxSEeofhgAueS

.gitignore

@@ -1,2 +1,7 @@
 /target
 .idea/**
+
+# makepkg build artifacts
+/packaging/pkg/
+/packaging/src/
+/packaging/*.pkg.tar.zst

README.md

@@ -111,6 +111,30 @@ excluded), so it's a real edge case, not a hypothetical. Not fixed for now
 since it takes a document engineered to trigger it, but worth knowing if a
 report seems to be missing something you know is in an uploaded document.
 
+## Installing (Arch/Manjaro)
+
+[`packaging/PKGBUILD`](./packaging/PKGBUILD) builds and installs `doubleo7`
+as a proper pacman package (`doubleo7-git`), pulling source straight from
+this repo's git history rather than a crates.io release:
+
+```
+cd packaging
+makepkg -si
+```
+
+`-s` resolves `makedepends` (`cargo`, `git`) via pacman first, `-i`
+installs the resulting package after building it. To pick up upstream
+changes later, just rerun the same command from a checkout with the latest
+commits — `pkgver()` derives its version from `git rev-list`/`git
+rev-parse`, so `makepkg` detects the new commit, rebuilds, and `pacman -U`
+replaces the old install in place. Uninstall with `sudo pacman -R
+doubleo7-git`.
+
+Note: Manjaro's default `CFLAGS`/`LDFLAGS` hardening flags corrupt the
+vendored C build inside `aws-lc-sys` (a transitive TLS dependency), causing
+a symbol-mismatch link error — `PKGBUILD`'s `build()` unsets them before
+invoking `cargo build` to work around it.
+
 ## Project layout
 
 Split one concern per file rather than one large module:

packaging/PKGBUILD

@@ -0,0 +1,47 @@
+# Maintainer: Austin Schaefer <schaefer.austin.p@inbox.eu>
+pkgname=doubleo7-git
+pkgver=0.2.0.r59.g8d7f8b6
+pkgrel=1
+pkgdesc="Local-first, multi-agent deep-research CLI"
+arch=('x86_64')
+url="https://code.austinschaefer.com/schaefera/doubleo7"
+license=('custom')
+depends=('gcc-libs')
+makedepends=('cargo' 'git' 'cmake')
+provides=('doubleo7')
+conflicts=('doubleo7')
+source=("$pkgname::git+ssh://git@51.15.208.55:22222/schaefera/doubleo7.git")
+sha256sums=('SKIP')
+
+pkgver() {
+  cd "$pkgname"
+  local base
+  base=$(grep -m1 '^version' Cargo.toml | cut -d '"' -f2)
+  printf "%s.r%s.g%s" "$base" "$(git rev-list --count HEAD)" "$(git rev-parse --short HEAD)"
+}
+
+prepare() {
+  cd "$pkgname"
+  cargo fetch --locked
+}
+
+build() {
+  cd "$pkgname"
+  export RUSTUP_TOOLCHAIN=stable
+  # Distro CFLAGS/LDFLAGS hardening flags corrupt aws-lc-sys's vendored C
+  # build (symbol-prefix mismatch at link time); build it with cc-rs's own
+  # defaults instead.
+  unset CFLAGS CXXFLAGS LDFLAGS CPPFLAGS
+  cargo build --frozen --release
+}
+
+check() {
+  cd "$pkgname"
+  cargo test --frozen --release
+}
+
+package() {
+  cd "$pkgname"
+  install -Dm755 "target/release/doubleo7" "$pkgdir/usr/bin/doubleo7"
+  install -Dm644 README.md "$pkgdir/usr/share/doc/$pkgname/README.md"
+}