Fix Shift+Enter in terminal input modes (#999)

* Fix Shift+Enter terminal input modes

* Advertise terminal input capabilities

packages/app/src/utils/terminal-keys.test.ts

@@ -95,7 +95,7 @@ describe("terminal key helpers", () => {
     ).toBe(true);
   });
 
-  it("intercepts Enter with DOM shift modifier for CSI u encoding", () => {
+  it("does not intercept modified Enter before enhanced input mode is active", () => {
     expect(
       shouldInterceptDomTerminalKey({
         key: "Enter",
@@ -105,10 +105,10 @@ describe("terminal key helpers", () => {
         metaKey: false,
         pendingModifiers: { ctrl: false, shift: false, alt: false },
       }),
-    ).toBe(true);
+    ).toBe(false);
   });
 
-  it("intercepts Enter with any DOM modifier for CSI u encoding", () => {
+  it("intercepts Enter with any DOM modifier after enhanced input mode is active", () => {
     expect(
       shouldInterceptDomTerminalKey({
         key: "Enter",
@@ -117,6 +117,7 @@ describe("terminal key helpers", () => {
         altKey: false,
         metaKey: false,
         pendingModifiers: { ctrl: false, shift: false, alt: false },
+        enhancedInputActive: true,
       }),
     ).toBe(true);
     expect(
@@ -127,6 +128,7 @@ describe("terminal key helpers", () => {
         altKey: true,
         metaKey: false,
         pendingModifiers: { ctrl: false, shift: false, alt: false },
+        enhancedInputActive: true,
       }),
     ).toBe(true);
     expect(
@@ -137,6 +139,7 @@ describe("terminal key helpers", () => {
         altKey: false,
         metaKey: true,
         pendingModifiers: { ctrl: false, shift: false, alt: false },
+        enhancedInputActive: true,
       }),
     ).toBe(true);
   });

packages/app/src/utils/terminal-keys.ts

@@ -89,15 +89,13 @@ export function shouldInterceptDomTerminalKey(args: {
   altKey: boolean;
   metaKey: boolean;
   pendingModifiers: PendingTerminalModifiers;
+  enhancedInputActive?: boolean;
 }): boolean {
   if (hasPendingTerminalModifiers(args.pendingModifiers)) {
     return true;
   }
-  // xterm.js sends plain \r for Enter regardless of modifiers.
-  // Intercept modified Enter so it gets CSI u encoding (Kitty keyboard protocol),
-  // which Claude Code and other TUI apps use for Shift+Enter newlines.
   if (args.key === "Enter" && (args.shiftKey || args.ctrlKey || args.altKey || args.metaKey)) {
-    return true;
+    return Boolean(args.enhancedInputActive);
   }
   return false;
 }