Fix terminal color query replies

Answer OSC color queries from the daemon and suppress browser-side replies so response bytes do not race back into the shell prompt as user input.

packages/app/e2e/terminal-protocol-query.spec.ts

@@ -0,0 +1,61 @@
+import { writeFile } from "node:fs/promises";
+import path from "node:path";
+import { test, expect } from "./fixtures";
+import { TerminalE2EHarness } from "./helpers/terminal-dsl";
+import { getTerminalBufferText, waitForTerminalContent } from "./helpers/terminal-perf";
+
+const OSC11_CAPTURE_SCRIPT = `
+let captured = Buffer.alloc(0);
+
+function finish() {
+  process.stdout.write("PASEO_OSC11_CAPTURE:" + JSON.stringify(captured.toString("latin1")) + "\\n");
+  process.exit(0);
+}
+
+process.stdout.write("\\x1b]11;?\\x07");
+if (process.stdin.isTTY) {
+  process.stdin.setRawMode(true);
+}
+process.stdin.resume();
+process.stdin.on("data", (chunk) => {
+  captured = Buffer.concat([captured, chunk]);
+  if (captured.includes(Buffer.from("rgb:"))) {
+    finish();
+  }
+});
+setTimeout(finish, 700);
+`;
+
+test.describe("Terminal protocol queries", () => {
+  let harness: TerminalE2EHarness;
+
+  test.beforeAll(async () => {
+    harness = await TerminalE2EHarness.create({ tempPrefix: "terminal-protocol-query-" });
+    await writeFile(path.join(harness.tempRepo.path, "osc11-capture.cjs"), OSC11_CAPTURE_SCRIPT);
+  });
+
+  test.afterAll(async () => {
+    await harness?.cleanup();
+  });
+
+  test("does not send browser OSC 11 color-query replies back to the PTY", async ({ page }) => {
+    const terminalInstance = await harness.createTerminal({ name: "osc11-query" });
+    try {
+      await harness.openTerminal(page, { terminalId: terminalInstance.id });
+      await harness.setupPrompt(page);
+
+      const terminal = harness.terminalSurface(page);
+      await terminal.pressSequentially("node osc11-capture.cjs\n", { delay: 0 });
+
+      await waitForTerminalContent(page, (text) => text.includes("PASEO_OSC11_CAPTURE:"), 10_000);
+      await page.waitForTimeout(500);
+
+      const text = await getTerminalBufferText(page);
+
+      expect(text).toContain("rgb:0b0b/0b0b/0b0b");
+      expect(text).not.toContain("rgb:ffff/ffff/ffff");
+    } finally {
+      await harness.killTerminal(terminalInstance.id);
+    }
+  });
+});

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

@@ -319,6 +319,9 @@ describe("terminal emulator runtime in a real browser", () => {
     { name: "DSR-?6", bytes: "\x1b[?6n" },
     { name: "DECRQM", bytes: "\x1b[1$p" },
     { name: "DECRQM-?", bytes: "\x1b[?1$p" },
+    { name: "OSC-10-foreground-color", bytes: "\x1b]10;?\x07" },
+    { name: "OSC-11-background-color", bytes: "\x1b]11;?\x07" },
+    { name: "OSC-12-cursor-color", bytes: "\x1b]12;?\x07" },
   ])("does not emit a PTY input reply for $name", async ({ bytes }) => {
     await page.viewport(900, 600);
     const mounted = createTerminalHost({ width: 720, height: 360 });

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

@@ -301,6 +301,9 @@ export class TerminalEmulatorRuntime {
         { prefix: "?", intermediates: "$", final: "p" },
         () => true,
       );
+      for (const code of [10, 11, 12]) {
+        terminal.parser.registerOscHandler(code, (data) => data.trim() === "?");
+      }
     };
     registerProtocolQuerySuppression();