fix(inbound): preserve literal backslash-n sequences in Windows paths (#11547)

* fix(inbound): preserve literal backslash-n sequences in Windows paths

The normalizeInboundTextNewlines function was converting literal backslash-n
sequences (\n) to actual newlines, corrupting Windows paths like
C:\Work\nxxx\README.md when sent through WebUI.

This fix removes the .replaceAll("\\n", "\n") operation, preserving
literal backslash-n sequences while still normalizing actual CRLF/CR to LF.

Fixes #7968

* fix(test): set RawBody to Windows path so BodyForAgent fallback chain tests correctly

* fix: tighten Windows path newline regression coverage (#11547) (thanks @mcaxtr)

---------

Co-authored-by: Peter Steinberger <steipete@gmail.com>

src/auto-reply/reply/inbound-text.test.ts

@@ -0,0 +1,35 @@
+import { describe, expect, it } from "vitest";
+import { normalizeInboundTextNewlines } from "./inbound-text.js";
+
+describe("normalizeInboundTextNewlines", () => {
+  it("converts CRLF to LF", () => {
+    expect(normalizeInboundTextNewlines("hello\r\nworld")).toBe("hello\nworld");
+  });
+
+  it("converts CR to LF", () => {
+    expect(normalizeInboundTextNewlines("hello\rworld")).toBe("hello\nworld");
+  });
+
+  it("preserves literal backslash-n sequences in Windows paths", () => {
+    // Windows paths like C:\Work\nxxx should NOT have \n converted to newlines
+    const windowsPath = "C:\\Work\\nxxx\\README.md";
+    expect(normalizeInboundTextNewlines(windowsPath)).toBe("C:\\Work\\nxxx\\README.md");
+  });
+
+  it("preserves backslash-n in messages containing Windows paths", () => {
+    const message = "Please read the file at C:\\Work\\nxxx\\README.md";
+    expect(normalizeInboundTextNewlines(message)).toBe(
+      "Please read the file at C:\\Work\\nxxx\\README.md",
+    );
+  });
+
+  it("preserves multiple backslash-n sequences", () => {
+    const message = "C:\\new\\notes\\nested";
+    expect(normalizeInboundTextNewlines(message)).toBe("C:\\new\\notes\\nested");
+  });
+
+  it("still normalizes actual CRLF while preserving backslash-n", () => {
+    const message = "Line 1\r\nC:\\Work\\nxxx";
+    expect(normalizeInboundTextNewlines(message)).toBe("Line 1\nC:\\Work\\nxxx");
+  });
+});

src/auto-reply/reply/inbound-text.ts

@@ -1,3 +1,6 @@
 export function normalizeInboundTextNewlines(input: string): string {
-  return input.replaceAll("\r\n", "\n").replaceAll("\r", "\n").replaceAll("\\n", "\n");
+  // Normalize actual newline characters (CR+LF and CR to LF).
+  // Do NOT replace literal backslash-n sequences (\\n) as they may be part of
+  // Windows paths like C:\Work\nxxx\README.md or user-intended escape sequences.
+  return input.replaceAll("\r\n", "\n").replaceAll("\r", "\n");
 }