swarm-ui: full-tab agent terminal (#4506)

Adds a full, non-capped agent terminal reachable from a new expand
trigger on the embedded AgentTermPreview (the detail-panel preview on
AgentsPage stays as-is, just gains the trigger). Opens
/agents/:name/terminal in a new dynamic tab in Shell's header, next to
the static nav row — tabs persist across a reload via useDynamicTabs,
a small localStorage-backed hook built on @hive/shared's existing
settings-storage primitive.

AgentTermPreview gains two new props to support both mounts from one
component: fullHeight (drops the 12em preview cap, fills its page)
and showHeaderBadges (default true — lets a future caller that
already shows turn_state/model/ctx/cost elsewhere suppress this
cluster; AgentsPage doesn't use it, see below).

Deviation from the originally posted plan (issue comment 80596): that
plan proposed AgentsPage's embedded preview pass showHeaderBadges as
false, reasoning the detail panel already duplicates that info.
Checked the actual code before implementing — it doesn't; AgentRow/
AgentTypes.ts carry none of turn_state/model/ctx/cost, and
AgentTermPreview's own floating badges are the only place swarm-ui
shows them. Left the badges visible there instead of shipping a
regression the plan's own stated justification didn't hold up to.

Also fixed a same-tab pub/sub race found by actually rendering a cold
load of /agents/:name/terminal (headless chromium, not just reasoning
about the code): useLocalSetting subscribes inside a useEffect, and
mount effects fire children-before-parents, so a descendant's
mount-time write (AgentTerminalPage registering its own tab) can beat
an ancestor's (Shell's) subscription into existence, leaving Shell's
tab row silently empty on a direct/reload load. Fixed by having
useDynamicTabs re-sync from storage on every location change, not
just on notify() — the fix lives in the new hook itself, not in the
shared settings-storage primitive theme/motion overrides also use.

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 { AgentTerminalPage } from "./pages/agents/AgentTerminalPage.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/terminal" component={AgentTerminalPage} />
         <Route path="/jobs" component={JobsPage} />
         <Route path="/issues" component={IssueReportPage} />
         <Route path="/components" component={ComponentsPage} />