Feat: add package signature

hl-base-env.install

@@ -1,5 +1,8 @@
 _package_changed() {
   trust anchor --store /usr/share/hl-base-env/hl-rootca.crt
+  pacman-key --add /usr/share/hl-base-env/hl-package.asc && \
+    pacman-key --lsign-key \
+      'Yi-Ting Shih Packaging Infrastructure <[email protected]>'
   update-ca-trust
 }