fix(app): refit terminal when returning to agent

packages/app/src/components/terminal-emulator.tsx

@@ -29,6 +29,7 @@ interface TerminalEmulatorProps {
   onOutputChunkConsumed?: (sequence: number) => Promise<void> | void;
   pendingModifiers?: PendingTerminalModifiers;
   focusRequestToken?: number;
+  resizeRequestToken?: number;
 }
 
 declare global {
@@ -51,6 +52,7 @@ export default function TerminalEmulator({
   onOutputChunkConsumed,
   pendingModifiers = { ctrl: false, shift: false, alt: false },
   focusRequestToken = 0,
+  resizeRequestToken = 0,
 }: TerminalEmulatorProps) {
   const rootRef = useRef<HTMLDivElement | null>(null);
   const hostRef = useRef<HTMLDivElement | null>(null);
@@ -142,6 +144,13 @@ export default function TerminalEmulator({
     runtimeRef.current?.focus();
   }, [focusRequestToken]);
 
+  useEffect(() => {
+    if (resizeRequestToken <= 0) {
+      return;
+    }
+    runtimeRef.current?.resize({ force: true });
+  }, [resizeRequestToken]);
+
   return (
     <div
       ref={rootRef}

packages/app/src/components/terminal-pane.tsx

@@ -1,5 +1,6 @@
 import { useCallback, useEffect, useMemo, useRef, useState } from "react";
 import { useMutation, useQuery, useQueryClient } from "@tanstack/react-query";
+import { useFocusEffect } from "@react-navigation/native";
 import {
   ActivityIndicator,
   Pressable,
@@ -45,6 +46,7 @@ interface TerminalPaneProps {
 
 const MAX_OUTPUT_CHARS = 200_000;
 const TERMINAL_TAB_MAX_WIDTH = 220;
+const TERMINAL_REFIT_DELAYS_MS = [0, 48, 144, 320];
 
 const MODIFIER_LABELS = {
   ctrl: "Ctrl",
@@ -159,6 +161,7 @@ export function TerminalPane({ serverId, cwd }: TerminalPaneProps) {
   const [streamError, setStreamError] = useState<string | null>(null);
   const [modifiers, setModifiers] = useState<ModifierState>(EMPTY_MODIFIERS);
   const [focusRequestToken, setFocusRequestToken] = useState(0);
+  const [resizeRequestToken, setResizeRequestToken] = useState(0);
   const [hoveredTerminalId, setHoveredTerminalId] = useState<string | null>(null);
   const [hoveredCloseTerminalId, setHoveredCloseTerminalId] = useState<string | null>(
     null
@@ -253,6 +256,30 @@ export function TerminalPane({ serverId, cwd }: TerminalPaneProps) {
   const requestTerminalFocus = useCallback(() => {
     setFocusRequestToken((current) => current + 1);
   }, []);
+  const requestTerminalReflow = useCallback(() => {
+    setResizeRequestToken((current) => current + 1);
+  }, []);
+
+  useFocusEffect(
+    useCallback(() => {
+      if (!selectedTerminalId) {
+        return;
+      }
+      // Navigation transitions can temporarily report stale dimensions.
+      // Pulse forced refits so xterm fills the pane when returning to an agent.
+      const timeoutHandles = TERMINAL_REFIT_DELAYS_MS.map((delayMs) =>
+        setTimeout(() => {
+          requestTerminalReflow();
+        }, delayMs)
+      );
+
+      return () => {
+        for (const handle of timeoutHandles) {
+          clearTimeout(handle);
+        }
+      };
+    }, [requestTerminalReflow, selectedTerminalId])
+  );
 
   const terminalsQuery = useQuery({
     queryKey: terminalsQueryKey,
@@ -938,6 +965,7 @@ export function TerminalPane({ serverId, cwd }: TerminalPaneProps) {
               onOutputChunkConsumed={handleOutputChunkConsumed}
               pendingModifiers={modifiers}
               focusRequestToken={focusRequestToken}
+              resizeRequestToken={resizeRequestToken}
             />
           </View>
         ) : (

packages/app/src/terminal/runtime/terminal-emulator-runtime.test.ts

@@ -157,4 +157,18 @@ describe("terminal-emulator-runtime", () => {
     expect(onCommittedA).toHaveBeenCalledTimes(1);
     expect(onCommittedB).toHaveBeenCalledTimes(1);
   });
+
+  it("forces a refit when resize is requested", () => {
+    const runtime = new TerminalEmulatorRuntime();
+    const fitAndEmitResize = vi.fn();
+
+    (runtime as unknown as { fitAndEmitResize: (force: boolean) => void }).fitAndEmitResize =
+      fitAndEmitResize;
+
+    runtime.resize();
+    runtime.resize({ force: true });
+
+    expect(fitAndEmitResize).toHaveBeenNthCalledWith(1, false);
+    expect(fitAndEmitResize).toHaveBeenNthCalledWith(2, true);
+  });
 });

packages/app/src/terminal/runtime/terminal-emulator-runtime.ts

@@ -76,6 +76,7 @@ export class TerminalEmulatorRuntime {
   };
   private terminal: Terminal | null = null;
   private fitAddon: FitAddon | null = null;
+  private fitAndEmitResize: ((force: boolean) => void) | null = null;
   private lastSize: { rows: number; cols: number } | null = null;
   private cleanup: (() => void) | null = null;
   private outputOperations: TerminalOutputOperation[] = [];
@@ -168,6 +169,7 @@ export class TerminalEmulatorRuntime {
         cols: nextCols,
       });
     };
+    this.fitAndEmitResize = fitAndEmitResize;
 
     fitAndEmitResize(true);
 
@@ -383,6 +385,10 @@ export class TerminalEmulatorRuntime {
     this.processOutputQueue();
   }
 
+  resize(input?: { force?: boolean }): void {
+    this.fitAndEmitResize?.(input?.force ?? false);
+  }
+
   focus(): void {
     this.terminal?.focus();
   }
@@ -413,6 +419,7 @@ export class TerminalEmulatorRuntime {
     }
     this.terminal = null;
     this.fitAddon = null;
+    this.fitAndEmitResize = null;
     this.lastSize = null;
   }