Add Image Embedding Provenance Pipeline

[NetZissou]

Adds processing/tol200m_image_embeddings/:

the SLURM jobs, configs, and standardization scripts used to produce the image embedding configs of TreeOfLife-200M-Embeddings (bioclip-2_float16, bioclip-2.5-vith14_float16)

Different models share the same pipeline, differing in weights, and normalization options:

1. Batch embedding: hpc-inference open_clip_embed over the TOL-200M HDF5 shards (multi-rank job for small sources; an image-count-balanced SLURM array for gbif). Outputs raw float32 embeddings.
2. Standardization: join to the TOL-200M catalog metadata via the published row order (keeps all configs row-aligned), global taxonomic sort, L2 normalization (BioCLIP 2.5 only), float16 cast, and contract parquet write.
3. Validation: counts, contract fields, full order check, sample recompute.

All site-specific paths and accounts are placeholders.