agent ui: add a clickable new-session menu entry

Same gap #4611 fixed for logout: the Preact rewrite's StatusChips menu
never picked up new-session as a click path, only /new-session typed
twice into the terminal. postNewSession already existed in
termActions.ts. Wire it into the status menu with the same arm-then-
confirm click pattern logout/cancel-turn already use.

Closes #4612

frontend/packages/agent/src/Root.tsx

@@ -27,7 +27,11 @@ import { fmtAge, fmtTokens } from "./lib/format.js";
 import { resolveDashboardBase } from "./lib/dashboardBase.js";
 import { submitPauseResume } from "./lib/pauseAction.js";
 import { postModel, postEffort } from "./lib/modelEffort.js";
-import { postCancelTurn, postLogout } from "./lib/termActions.js";
+import {
+  postCancelTurn,
+  postLogout,
+  postNewSession,
+} from "./lib/termActions.js";
 import type { TokenUsage } from "./types.js";
 
 type OpenPanel = "inbox" | "todos" | null;
@@ -225,6 +229,7 @@ export function Root() {
               onTogglePause={() => {}}
               thinking={false}
               onCancelTurn={() => Promise.resolve()}
+              onNewSession={() => Promise.resolve()}
               onLogout={() => Promise.resolve()}
             />
           </Header>
@@ -332,6 +337,15 @@ export function Root() {
                 refresh();
               })
             }
+            onNewSession={() =>
+              postNewSession().then((r) => {
+                if (!r.ok)
+                  liveStreamRef.current?.pushNote(
+                    `✗ /new-session failed${r.detail ? ": " + r.detail : ""}`,
+                  );
+                refresh();
+              })
+            }
             onLogout={() =>
               postLogout().then((r) => {
                 if (!r.ok)

frontend/packages/agent/src/components/StatusChips.tsx

@@ -37,6 +37,12 @@ export interface StatusChipsProps {
   lastTurnLabel?: string;
   thinking: boolean;
   onCancelTurn: () => Promise<void>;
+  /** Drops all prior `--continue` context and starts fresh. Always
+   * offered, same as logout — the old app.js overflow menu had it as
+   * an unconditional click target too, this is just the click path
+   * catching up to what `/new-session` already does. See
+   * `termActions.ts`'s `postNewSession`. */
+  onNewSession: () => Promise<void>;
   /** Rotates OAuth creds + parks the agent in needs-login. Always
    * offered (unlike cancel-turn, not gated on `thinking`) — the old
    * page's overflow menu had it unconditionally too. See
@@ -119,6 +125,7 @@ function StatusMenu({
   onTogglePause,
   thinking,
   onCancelTurn,
+  onNewSession,
   onLogout,
 }: Pick<
   StatusChipsProps,
@@ -129,16 +136,19 @@ function StatusMenu({
   | "onTogglePause"
   | "thinking"
   | "onCancelTurn"
+  | "onNewSession"
   | "onLogout"
 >) {
   const [open, setOpen] = useState(false);
   const [confirmCancel, setConfirmCancel] = useState(false);
+  const [confirmNewSession, setConfirmNewSession] = useState(false);
   const [confirmLogout, setConfirmLogout] = useState(false);
   const anchorRef = useRef<HTMLDivElement>(null);
 
   function close() {
     setOpen(false);
     setConfirmCancel(false);
+    setConfirmNewSession(false);
     setConfirmLogout(false);
   }
 
@@ -153,7 +163,12 @@ function StatusMenu({
     });
   }
   // Always offered, regardless of turn state — same as the old overflow
-  // menu's unconditional 🔓 logout entry.
+  // menu's unconditional ↻ new-session and 🔓 logout entries.
+  options.push({
+    value: "new-session",
+    label: confirmNewSession ? "↻ click again to confirm" : "↻ new session",
+    danger: true,
+  });
   options.push({
     value: "logout",
     label: confirmLogout ? "🔓 click again to confirm" : "🔓 logout",
@@ -189,6 +204,16 @@ function StatusMenu({
             close();
             return;
           }
+          if (value === "new-session") {
+            // Same arm-then-fire shape as cancel-turn/logout.
+            if (!confirmNewSession) {
+              setConfirmNewSession(true);
+              return;
+            }
+            onNewSession();
+            close();
+            return;
+          }
           // value === 'logout': same arm-then-fire shape as cancel-turn.
           if (!confirmLogout) {
             setConfirmLogout(true);
@@ -222,6 +247,7 @@ export function StatusChips({
   lastTurnLabel,
   thinking,
   onCancelTurn,
+  onNewSession,
   onLogout,
 }: StatusChipsProps) {
   return (
@@ -234,6 +260,7 @@ export function StatusChips({
         onTogglePause={onTogglePause}
         thinking={thinking}
         onCancelTurn={onCancelTurn}
+        onNewSession={onNewSession}
         onLogout={onLogout}
       />
       <Picker