Add Cnchi PKGBUILD with local package support

- Add packages/cnchi/PKGBUILD building from Antergos-NeXT/Cnchi fork
- Add cnchi.install post-install script
- Update packages.yaml to include cnchi
- Update build-packages.py to prefer local PKGBUILDs over AUR

build-packages.py

@@ -10,16 +10,20 @@ with open("packages.yaml") as f:
 os.makedirs("/tmp/pkgout", exist_ok=True)
 
 for pkg in pkgs:
-    clone_dir = f"/tmp/{pkg}"
-    
-    if os.path.exists(clone_dir):
-        shutil.rmtree(clone_dir)
-    
-    subprocess.run(["git", "clone", f"https://aur.archlinux.org/{pkg}.git", clone_dir])
-    
-    subprocess.run(["chown", "-R", "builder:builder", clone_dir])
-    subprocess.run(["su", "-", "builder", "-c", f"cd {clone_dir} && makepkg -s --noconfirm --noprogress --skippgpcheck --skipinteg"])
-    
-    subprocess.run(f"cp {clone_dir}/*.pkg.tar.zst /tmp/pkgout/ || true", shell=True)
+    local_pkgbuild = f"packages/{pkg}/PKGBUILD"
+    build_dir = f"/tmp/{pkg}"
+
+    if os.path.exists(build_dir):
+        shutil.rmtree(build_dir)
+
+    if os.path.exists(local_pkgbuild):
+        shutil.copytree(f"packages/{pkg}", build_dir)
+    else:
+        subprocess.run(["git", "clone", f"https://aur.archlinux.org/{pkg}.git", build_dir])
+
+    subprocess.run(["chown", "-R", "builder:builder", build_dir])
+    subprocess.run(["su", "-", "builder", "-c", f"cd {build_dir} && makepkg -s --noconfirm --noprogress --skippgpcheck --skipinteg"])
+
+    subprocess.run(f"cp {build_dir}/*.pkg.tar.zst /tmp/pkgout/ || true", shell=True)
 
 print("Done!")