missions: extract MissionLivePane to stay under 1500-LoC CI budget

Previous push hit the gates job's file-size gate — MissionCanvas.tsx
was 1517 lines (17 over). The Live Pane xterm subcomponent is
cleanly separable (no shared state with the parent, just takes
nodeId + visible props), so it lifts into its own file at zero
behavior cost.

  frontend/src/components/dashboard/MissionLivePane.tsx  (new, 106 LoC)
  frontend/src/components/dashboard/MissionCanvas.tsx    (1517 → 1424)

Also drops the xterm.css + useResilientTerminal imports from
MissionCanvas since only MissionLivePane needs them now.

frontend/src/components/dashboard/MissionCanvas.tsx

@@ -29,13 +29,8 @@ import {
   type TemplateKind,
 } from "@/lib/api/missions";
 import { MarkdownBlock } from "./MarkdownBlock";
+import { MissionLivePane } from "./MissionLivePane";
 import { MissionWizard } from "./MissionWizard";
-import {
-  nodeHerdrConnector,
-  useResilientTerminal,
-  type TermMode,
-} from "@/components/computer/apps/terminal/core";
-import "@xterm/xterm/css/xterm.css";
 
 const mono =
   "ui-monospace, SFMono-Regular, SF Mono, Menlo, Monaco, Consolas, monospace";
@@ -935,7 +930,7 @@ export function MissionCanvas({
         )}
 
         {tab === "pane" && mission.runtime_kind === "local_herdr" && (
-          <LivePane
+          <MissionLivePane
             nodeId={mission.target_node_id}
             visible={tab === "pane"}
           />
@@ -992,94 +987,6 @@ function Empty({ label }: { label: string }) {
   );
 }
 
-function LivePane({
-  nodeId,
-  visible,
-}: {
-  nodeId: string | null;
-  visible: boolean;
-}) {
-  if (!nodeId) {
-    return (
-      <div
-        style={{
-          padding: 40,
-          textAlign: "center",
-          color: "#8a8a92",
-          fontSize: 13,
-        }}
-      >
-        This mission has no target node.
-      </div>
-    );
-  }
-  return <LivePaneInner nodeId={nodeId} visible={visible} />;
-}
-
-function LivePaneInner({
-  nodeId,
-  visible,
-}: {
-  nodeId: string;
-  visible: boolean;
-}) {
-  const [mode, setMode] = useState<TermMode>("connecting");
-  const { hostRef, refit } = useResilientTerminal(
-    {
-      connect: nodeHerdrConnector(nodeId, setMode),
-      autoFocus: false,
-      visible: () => visible,
-    },
-    [nodeId],
-  );
-  useEffect(() => {
-    if (visible) refit();
-  }, [visible, refit]);
-  return (
-    <div
-      style={{
-        position: "relative",
-        height: "70vh",
-        minHeight: 480,
-        background: "#0a0a0d",
-        borderRadius: 10,
-        border: "1px solid rgba(255,255,255,.06)",
-        overflow: "hidden",
-      }}
-    >
-      <div
-        style={{
-          position: "absolute",
-          top: 8,
-          right: 8,
-          zIndex: 5,
-          padding: "2px 8px",
-          borderRadius: 6,
-          fontFamily: mono,
-          fontSize: 10,
-          letterSpacing: ".1em",
-          textTransform: "uppercase",
-          color:
-            mode === "direct"
-              ? "#5fd08a"
-              : mode === "relayed"
-                ? "#8a8a92"
-                : "#e8b465",
-          background:
-            mode === "direct"
-              ? "rgba(95,208,138,.12)"
-              : "rgba(255,255,255,.05)",
-          border: `1px solid ${
-            mode === "direct" ? "rgba(95,208,138,.3)" : "rgba(255,255,255,.1)"
-          }`,
-        }}
-      >
-        {mode === "direct" ? "direct" : mode === "relayed" ? "relayed" : "connecting…"}
-      </div>
-      <div ref={hostRef} style={{ position: "absolute", inset: 0, padding: 8 }} />
-    </div>
-  );
-}
 
 function EditMissionModal({
   mission,