Header-bar parity for the swarm-level agent terminal, per mara's ruling
"dont make it a header though - make it floating elements on top of the
terminal". Adds useSwarmAgentStateStream (SSE consumer for
swarm-controller's GET /api/agents/{name}/state/stream) and renders a
small read-only Badge cluster absolutely positioned in
AgentTermPreview's terminal box corner, reusing the same anchor pattern
@hive/shared/terminal.css's .tail-pill already uses.
Shows turn_state always, agent_state only when it isn't the boring "up"
case, model (with resolved-model tooltip), and ctx/cost usage. No badge
renders until the first header event lands - the swarm queue's
agent-state subject is transition-only with no seed/replay, and no
swarm-level endpoint today can seed turn_state/model/ctx/cost
synchronously.
Vocabulary (state tones, token-total/format helpers) ported from
@hive/agent's Root.tsx/lib/format.ts rather than imported, matching the
existing "small helper, not worth a cross-package hop" call
useSwarmTermStream's own appendRow already made.
Verified by rendering the real component tree against a stubbed
EventSource and screenshotting the result - the badge cluster initially
overlapped the terminal's first row of text, fixed by giving this
preview's own .live.terminal extra top padding.
d9c8b7ca8f