- export_presets.cfg: new "Linux ARM64" preset (arch arm64, embedded PCK,
ETC2/ASTC textures, S3TC/BPTC off since the Pi 5 V3D driver lacks it).
- tools/zipfetch.py: pull a single member out of the remote export-templates
tpz with HTTP Range requests instead of downloading the whole 1.28 GB.
- docs/BUILD-RASPBERRY-PI.md: reproducible procedure, Pi 5 renderer
expectations (GLES3 fallback, Forward+ downgraded to Mobile) and the
pitfalls verified on the field.
Verified: arm64 export produced (74.094.536 B, PCK embedded at the end of the
official template); the x86_64 export from the same tree runs without missing
resources.