fix permissions on build dir

[jtrotsky]

Problem

After #7 the core-plugin path is correct, but plugins still don't load: Immich runs as bsd (uid 1000) and scans /build/plugins, which is created root-owned, mode 0700. The bsd process gets EACCES and registers zero plugins, so the Workflow builder is empty.

Cause: chown -R bsd:bsd /build runs before mkdir -p /build/plugins, and the only follow-up chown is chown -h on the symlink — never the directory.

Fix

mkdir -p /build/plugins && \
chown bsd:bsd /build/plugins && chmod 755 /build/plugins && \
ln -sf /app/corePlugin /build/plugins/immich-plugin-core && \

Verified

Rebuilt image, as the runtime user:

$ podman run --rm --user 1000:1000 --entrypoint sh <img> \
    -c 'ls -ld /build/plugins; head -c60 /build/plugins/immich-plugin-core/manifest.json'
drwxr-xr-x  bsd bsd  /build/plugins        # was drwx------ root
{ "name": "immich-plugin-core", ...       # was: Permission denied

/build/plugins is now traversable by uid 1000 and the plugin manifest reads. Runtime confirmation (/api/plugins/templates non-empty) pending a live deploy.