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} />