Keiki swarm controls: group roster, conversation liveness, background tasks with Cancel / End all

[devin-ai-integration]

Summary

Desktop counterpart of Mail-0/sms-kit#1000 (swarm observability). Depends on those platform routes being deployed; on older servers the new fields default to empty (#[serde(default)]) and the roster/end/cancel calls fail with their HTTP error, nothing else changes.

keiki-model / keiki-api — new models ConversationLiveness, SubagentTaskSummary, AgentGroupRoster{members, totals}, and client methods:

GET  /api/webapp/agent-groups/{id}/roster   -> AgentGroupRoster
POST /api/webapp/agent-groups/{id}/end      -> { threadsEnded, tasksCancelled }
POST /api/webapp/subagent-tasks/{id}/cancel -> { cancelled }

ConversationSummary/ConversationDetail gain liveness: Option<ConversationLiveness>; detail gains tasks: Vec<SubagentTaskSummary>.

UI — remote-only state lives in AppState (no engine/proto/persistence changes):

• keiki_liveness: chat_id -> Option<Liveness> written by both the 15 s snapshot loop and the selected-conversation detail poll; the session title bar shows a Working / Waiting on peer badge.
• KeikiConversation.tasks from the detail poll feeds a new right-pane Tasks surface (status pill, request, timestamps). Cancel on running/suspended tasks only when KeikiSessionInfo::can_manage() (role owner/admin — server is still authoritative).
• keiki_group_rosters: group_id -> AgentGroupRoster, polled in the snapshot loop for every expanded sidebar group; the expanded set is derived from settings.sidebar_collapsed_groups (Shell::sync_keiki_expanded_groups) so groups already open at launch poll too. Group header shows N members · running · waiting · $cost; expanded body lists ≤25 members (running → waiting → idle → ended) with a +N more row. End all (stop icon, manage roles, only when something is live) confirms with the live thread/task counts, calls end_agent_group, refreshes the roster, and surfaces 403/errors via notify.
• authorized_request wraps the credential read + token refresh for the two new mutating calls.

Verification

cargo fmt --check, cargo check -p zeron-ui, cargo test -p keiki-model (serde round-trip + defaulting for missing liveness/tasks), cargo test -p zeron-ui shell (58 passed). Not driven in the GUI against a live server.

Link to Devin session: https://app.devin.ai/sessions/e39718f873d847298776b2e2fdc14fcc
Open in Devin Desktop: https://app.devin.ai/desktop/session/e39718f873d847298776b2e2fdc14fcc?variant=devin
Requested by: @MrgSub

[devin-ai-integration]

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