Move file discovery (CLAUDE.md/POC.md, memory files, people/ glob),
prompt assembly, and context_file_info from config.rs into identity.rs.
All extracted functions are pure — they take paths and return strings,
with no dependency on AppConfig. config.rs calls into identity.rs
(one-way dependency).
config.rs: 663 → 440 lines (-223)
identity.rs: 232 lines (new)
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
