Nothing capped how many subagents an agent runs at once; the operator
wants to set that per agent from swarm-ui (#5234, shape (b)).
AgentInference gains `max_subagents: Option<u32>`. An absent field
decodes as None, so every stored value still parses and means "no cap",
which is today's behaviour.
swarm-controller accepts 1..=32 on PUT. 0 would refuse every start; 32
is far more concurrent claude sessions than one agent container has
memory for, so anything above it is a typo, not a cap.
The subagent daemon already read the agent's agent-inference key for
subagent_models; it now reads it on every start and continue (not only
those naming a model) and refuses a new run once the cap's worth of
names is tracked, counted under the same lock as the name reservation.
Every tracked slot counts: running, starting, a goal run between turns,
and an interrupted one still exiting. A goal re-prompt never goes
through the reservation, so it is never refused. A failed read applies
no cap, as it falls back for models.
swarmctl's `inference set` does GET, merge, PUT; its mirror type now
carries the field so a set from the CLI keeps a cap set in swarm-ui
instead of dropping it, and `get` prints it.
The hive reads the caps about every 30 seconds and a running agent takes a
changed cap at its next spawn or rebuild, so the dialog and the ui doc no
longer say the hive applies a change within seconds.
A resource caps row in the agent details reads GET /api/agents/{name}/limits
and shows the cpu quota and memory max, each reading as the hive deciding
when the swarm sets none. An edit dialog PUTs the filled fields, which
replaces the stored value whole, and a clear action DELETEs it. A refusal,
such as a percentage with a leading zero, shows as the route's reason under
the fields and leaves them as typed.
The details open under the agent badge without dimming or blocking the page; a click outside or Escape closes it. New ui/popover primitive (anchored, portal, no backdrop) with a sample on the components page. A confirm or link dialog opened from inside it stays modal, and the popover ignores clicks and Escape that belong to that dialog. AgentDetailDialog becomes AgentDetailPopover.
pages/agents held the roster page, the terminal page and every component under them. It keeps the two pages; the components move to src/agent, by concern: roster (card, wanted menu, actions), detail (panel body, dialog, inference, linked accounts, link menu) and terminal (preview, input, subagents, stream hooks, favicon), with the shared row type and icon at the top. Moves and import rewrites only.
