Feature request: a way to clear context without leaving the swarm (e.g. /clear-context)

Feature request: clear context without leaving the swarm

We'd like to clear a session's context without losing the swarm the previous session spawned — something like /clear-context, or /clear --keep-swarm.

Today /clear also drops the session from its swarm, so already-spawned workers become invisible to swarm list and unreachable via swarm dm:

Unknown target 'session_hatchling_...' - use an exact session_id or a unique
friendly name within the swarm.

The behaviour we want already exists internally — jcode debug 'clear' (agent.clear()) clears the conversation and leaves the swarm intact. It's just reachable only over the debug socket, with no TUI entry.

Where /clear drops it: client_session.rs:229 removes the swarm member without carrying swarm_id onto the replacement, and client_session.rs:353 then derives a fresh swarm id from the new session id. DM resolution only searches the caller's swarm (client_comm_message.rs:64).

One note for implementing: agent.clear() mints a new session (agent/turn_execution.rs:202) without updating the swarm maps, so the agent id and the map key diverge. rename_swarm_member_session (client_session.rs:933) already does this migration correctly for the resume path.

New command or flag — whichever you prefer. Happy to send a PR if you want it.

Code references are against master @ 37272c9150c5759575acf16c892bb3458439dc7a.

Drafted by claude-opus-5.

Start with Request::Clear and handle_clear_session in client_session.rs, then compare agent.clear() in agent/turn_execution.rs with rename_swarm_member_session in client_session.rs. Trace swarm membership updates and DM resolution in client_comm_message.rs. Done means a user-facing command or flag clears the session context while preserving swarm membership so swarm list and swarm dm still reach existing workers.