Is your feature request related to a problem? Please describe. Currently context for coding agents is limited to top-level directory, we need more granular context to keep context window clean. Also CLAUDE.md file is not applicable to all coding agents so we need a more general AGENTS.md file.
Describe the solution you'd like Add coding agent context files at a module level for the solana-app.
Additional context Starting point would be to create files for the solana-app (app/solana/cmd/app) and then for the modules in the API directory.