Search annex data

Dedicated search channels for external mappings and future annex datasets.

This entry point is separate from genome, gene, and cluster search so we can add annex-specific searches without overloading the core catalog forms.

External mappings

RefSeq, UniProt, GO, and PubMed links resolved from p2cs_annexes.db

Use this channel to search identifiers and literature-oriented annotations, then jump back to linked P2CS genes and clusters when a mapping exists.

Future annex searches

Reserved for upcoming datasets

Additional annex channels can be added here later without changing the global `Search` menu again.