swarm-ui: read-only agent terminal page consuming the swarm term stream

Moves the TermMsg rendering pipeline (Row.tsx, termMsg.ts, linkify.tsx,
markdown.ts) from @hive/agent into @hive/shared, so swarm-ui becomes a
second consumer of it instead of forking a copy -- CSS was already
shared (@hive/shared/terminal.css). marked+dompurify move from
@hive/agent's deps to @hive/shared's; swarm-ui picks them up
transitively, no new direct dep there.

New swarm-ui route /agents/:name/term (AgentTermPage), linked from
AgentsPage's detail panel via a "terminal" badge next to "link matrix
account". Consumes GET /api/agents/{name}/term/stream: unlike
@hive/agent's own useLiveStream (TermEnvelope-wrapped, history/backfill
dance), the swarm relay forwards one bare TermMsg per SSE event with no
envelope and no history endpoint -- useSwarmTermStream is a much
smaller hook for that shape (EventSource -> parse -> coalesce, nothing
to buffer/dedupe/backfill against).

Verified against a live SSE mock (screenshots in /agents/iris/state/screenshots/
3801-agents-detail-panel-terminal-badge.png and
3801-agent-term-page-live-rows.png -- real rows rendering through the
shared Row component, not just a build/typecheck pass).

frontend/packages/swarm-ui/src/App.tsx

@@ -3,6 +3,7 @@
 import { Route, Switch } from "wouter-preact";
 import { Shell } from "./shell/Shell.js";
 import { AgentsPage } from "./pages/agents/AgentsPage.js";
+import { AgentTermPage } from "./pages/agents/AgentTermPage.js";
 import { ComponentsPage } from "./pages/ComponentsPage.js";
 import { JobsPage } from "./pages/JobsPage.js";
 import { HivesPage } from "./pages/HivesPage.js";
@@ -23,6 +24,7 @@ export function App() {
       <Switch>
         <Route path="/" component={HivesPage} />
         <Route path="/agents" component={AgentsPage} />
+        <Route path="/agents/:name/term" component={AgentTermPage} />
         <Route path="/jobs" component={JobsPage} />
         <Route path="/issues" component={IssueReportPage} />
         <Route path="/components" component={ComponentsPage} />

frontend/packages/swarm-ui/src/pages/agents/AgentTermPage.css

@@ -0,0 +1,20 @@
+/* <AgentTermPage> — `.terminal-wrap`/`.live.terminal` come from
+   @hive/shared/terminal.css unstyled (its own default 32em max-height
+   + scroll is exactly right here, no page override needed). Just
+   spacing for the status badge + back link this page adds around it. */
+@import "@hive/shared/terminal.css";
+
+.ui-agent-term-status {
+  display: inline-flex;
+  margin-block-end: 0.5rem;
+}
+
+.ui-agent-term-back {
+  font-size: 0.85rem;
+  color: var(--fg);
+  text-decoration: none;
+}
+
+.ui-agent-term-back:hover {
+  text-decoration: underline;
+}

frontend/packages/swarm-ui/src/pages/agents/AgentTermPage.tsx

@@ -0,0 +1,88 @@
+// <AgentTermPage> — read-only live terminal for one agent, consuming
+// swarm-controller's `GET /api/agents/{name}/term/stream`. First
+// per-agent detail route in swarm-ui (linked from `AgentsPage`'s detail
+// panel). Live-only, no backfill/history — see `useSwarmTermStream`'s
+// doc for why a fresh visit starts empty rather than replaying anything.
+//
+// Auto-scroll is the simple "stick to bottom unless the operator
+// scrolled up" rule `@hive/agent`'s `LiveStream` uses, minus its
+// load-more/history plumbing (nothing to load older here).
+import { useLayoutEffect, useRef, useState } from "preact/hooks";
+import { Link, useParams } from "wouter-preact";
+import { Badge, type BadgeTone } from "@hive/shared/badge.js";
+import { Row } from "@hive/shared/term-row.js";
+import { Panel } from "../../ui/panel/Panel.js";
+import { useSwarmTermStream, type ConnectionState } from "./useSwarmTermStream.js";
+import "./AgentTermPage.css";
+
+const NEAR_BOTTOM_PX = 48;
+
+const CONNECTION_LABEL: Record<ConnectionState, string> = {
+  connecting: "connecting…",
+  open: "live",
+  reconnecting: "reconnecting…",
+  closed: "disconnected",
+};
+
+const CONNECTION_TONE: Record<ConnectionState, BadgeTone> = {
+  connecting: "neutral",
+  open: "positive",
+  reconnecting: "warning",
+  closed: "negative",
+};
+
+export function AgentTermPage() {
+  const { name } = useParams<{ name: string }>();
+  const { rows, connection } = useSwarmTermStream(
+    `/api/agents/${encodeURIComponent(name ?? "")}/term/stream`,
+  );
+  const logRef = useRef<HTMLDivElement>(null);
+  const [stickToBottom, setStickToBottom] = useState(true);
+
+  function handleScroll() {
+    const el = logRef.current;
+    if (!el) return;
+    setStickToBottom(
+      el.scrollHeight - el.scrollTop - el.clientHeight <= NEAR_BOTTOM_PX,
+    );
+  }
+
+  // Runs after Preact has committed new rows, so `scrollHeight` is
+  // already current — same ordering `LiveStream`'s own layout effect
+  // relies on.
+  useLayoutEffect(() => {
+    const el = logRef.current;
+    if (el && stickToBottom) el.scrollTop = el.scrollHeight - el.clientHeight;
+  }, [rows, stickToBottom]);
+
+  return (
+    <Panel
+      title={`terminal — ${name}`}
+      icon="🖥️"
+      actions={
+        <Link to="/agents" class="ui-agent-term-back">
+          ← agents
+        </Link>
+      }
+    >
+      <Badge
+        class="ui-agent-term-status"
+        tone={CONNECTION_TONE[connection]}
+        value={CONNECTION_LABEL[connection]}
+      />
+      <div class="terminal-wrap">
+        <div class="live terminal" ref={logRef} onScroll={handleScroll}>
+          {rows.length === 0 ? (
+            <div class="row note">
+              {connection === "open"
+                ? "(connected — waiting for events)"
+                : CONNECTION_LABEL[connection]}
+            </div>
+          ) : (
+            rows.map((row) => <Row key={row.key} row={row} />)
+          )}
+        </div>
+      </div>
+    </Panel>
+  );
+}

frontend/packages/swarm-ui/src/pages/agents/AgentsPage.tsx

@@ -26,6 +26,7 @@
 // see its own comment) — `viewMode` here just says which one to show.
 import { useState } from "preact/hooks";
 import type { ComponentChildren } from "preact";
+import { useLocation } from "wouter-preact";
 import { ApiErrorPanel } from "@hive/shared/api-error-panel.js";
 import { readApiError, type ProblemDetails } from "@hive/shared/api-error.js";
 import { Badge } from "@hive/shared/badge.js";
@@ -95,6 +96,7 @@ type ViewMode = "cards" | "table";
 const VIEW_MODE_KEY = "swarm-ui:agents:view-mode";
 
 export function AgentsPage() {
+  const [, navigate] = useLocation();
   const [rows, setRows] = useState<AgentRow[] | null>(null);
   const [error, setError] = useState<ProblemDetails | null>(null);
   const [intervalMs, setIntervalMs] =
@@ -564,6 +566,17 @@ export function AgentsPage() {
                   </dd>
                 </dl>
                 <div class="ui-agent-detail-actions">
+                  <Badge
+                    variant="quiet"
+                    icon="🖥️"
+                    value="terminal"
+                    onClick={() =>
+                      navigate(
+                        `/agents/${encodeURIComponent(detailTarget.name)}/term`,
+                      )
+                    }
+                    title={`view ${detailTarget.name}'s live terminal`}
+                  />
                   <Badge
                     variant="quiet"
                     icon={<LinkIcon />}

frontend/packages/swarm-ui/src/pages/agents/useSwarmTermStream.ts

@@ -0,0 +1,70 @@
+// Live SSE consumer for the swarm-relayed agent terminal
+// (`GET /api/agents/{name}/term/stream`, swarm-controller's
+// `term_stream.rs`). Deliberately NOT `@hive/agent`'s `useLiveStream` —
+// that hook's wire shape is `TermEnvelope` (`{seq, msgs: []}`) plus a
+// history/backfill dance; the swarm relay forwards one bare `TermMsg`
+// per SSE event with no envelope and no history endpoint (a core NATS
+// subject, not `JetStream` — see `term_stream.rs`'s own module doc), so
+// there's nothing to buffer/dedupe/backfill against. Same row-coalescing
+// rule as `useLiveStream`'s `appendRow` (ported, not imported — one
+// small helper isn't worth a cross-package hop for).
+import { useEffect, useRef, useState } from "preact/hooks";
+import type { TermMsg, TermRow } from "@hive/shared/term-msg.js";
+
+export type ConnectionState =
+  | "connecting"
+  | "open"
+  | "reconnecting"
+  | "closed";
+
+function appendRow(rows: TermRow[], row: TermRow): TermRow[] {
+  const last = rows[rows.length - 1];
+  if (row.coalesce_key && last && last.coalesce_key === row.coalesce_key) {
+    return [...rows.slice(0, -1), { ...row, key: last.key }];
+  }
+  return [...rows, row];
+}
+
+export interface UseSwarmTermStreamResult {
+  rows: TermRow[];
+  connection: ConnectionState;
+}
+
+export function useSwarmTermStream(streamUrl: string): UseSwarmTermStreamResult {
+  const [rows, setRows] = useState<TermRow[]>([]);
+  const [connection, setConnection] = useState<ConnectionState>("connecting");
+  const keySeqRef = useRef(0);
+
+  useEffect(() => {
+    setRows([]);
+    setConnection("connecting");
+    keySeqRef.current = 0;
+    const es = new EventSource(streamUrl);
+    es.onopen = () => setConnection("open");
+    es.onmessage = (e) => {
+      keySeqRef.current += 1;
+      const key = "r" + keySeqRef.current;
+      let msg: TermMsg;
+      try {
+        msg = JSON.parse(e.data);
+      } catch {
+        setRows((prev) =>
+          appendRow(prev, {
+            key,
+            level: "warn",
+            fromHistory: false,
+            summary: "[parse err] " + e.data,
+          }),
+        );
+        return;
+      }
+      setRows((prev) => appendRow(prev, { ...msg, key, fromHistory: false }));
+    };
+    es.onerror = () => {
+      setConnection(es.readyState === 0 /* CONNECTING */ ? "reconnecting" : "closed");
+    };
+    return () => es.close();
+  }, [streamUrl]);
+
+  return { rows, connection };
+}