fix(ci): exclude CI artifacts/ directory from release ZIPs (#12)

download-artifact@v4 dumps raw build outputs (~159MB) into artifacts/
which was never excluded from the zip commands. Release ZIP bloated
from ~5MB to ~49MB as a result.

Author: Enginex0

.github/workflows/build.yml

@@ -163,6 +163,7 @@ jobs:
             -x ".gitmodules" \
             -x ".github/*" \
             -x "external/*" \
+            -x "artifacts/*" \
             -x "CLAUDE.md" \
             -x "*.zip" \
             -x "*.db" -x "*.db-shm" -x "*.db-wal" \

package.sh

@@ -174,6 +174,7 @@ zip -r9 "$ZIP_PATH" . \
     -x ".gitmodules" \
     -x ".github/*" \
     -x "external/*" \
+    -x "artifacts/*" \
     -x "CLAUDE.md" \
     -x "*.zip" \
     -x "*.db" -x "*.db-shm" -x "*.db-wal" \