Extend delegation system with 5 new specialized roles alongside
researcher/analyst/reviewer. Each role has curated tool access.
Refactor profile lookup to use profile_for_role_name and update
compact/summarizer and tool context accordingly.
Extract agent, compact, embed, task, and modes modules from single
service.rs files into focused sub-modules. Add orao module for
O1-like reasoning loop. Move RigAgentService to rig_tool.rs.
