Athena primary should not be routable via switch_agent or appear in the
delegation table. Only athena-junior (subagent) remains delegatable via task().
- Remove athena from ALLOWED_AGENTS and DESCRIPTION in switch-agent tool
- Remove ATHENA_PROMPT_METADATA from agentMetadata, agent.ts, barrel export
- Update switch-agent test to assert athena rejection
- Remove ATHENA_PROMPT_METADATA test block
Adopt the opencode-handoff pattern: switch_agent now creates a new session
and sends the context via promptAsync immediately in the tool's execute
function, then navigates the TUI to the new session.
Removes ~1700 LOC of complexity: persistent state management, event-based
hook monitoring, retry logic, session idle waiting, apply verification,
and terminal detection — all replaced by 3 SDK calls.
Deleted: src/features/agent-switch/ (14 files), src/hooks/agent-switch/ (4 files)
Updated: Athena prompt to announce handoff before calling switch_agent
ismeth