fix(rtk/find): detect and group Windows backslash-style find output (#2448)

isPathLike rejected any line with a colon, so Windows absolute paths
(C:\Users\me\a.js) were never recognized and find dumps went uncompacted.
find.js also split only on "/", mis-grouping backslash paths.

- autodetect: treat drive-letter prefix (X:\ or X:/) as path-like before
  the general colon rejection.
- find.js: split on the last "/" or "\" separator and normalize emitted
  directory labels to forward slashes.

Co-authored-by: Cursor <cursoragent@cursor.com>

open-sse/rtk/autodetect.js

@@ -84,6 +84,11 @@ function isGrepLine(line) {
 function isPathLike(line) {
   const t = line.trim();
   if (t.length === 0) return false;
+  // A drive-letter prefix (e.g. "C:\Users\me" or "C:/Users/me") marks a
+  // Windows absolute path, so treat the whole line as path-like. Trailing
+  // colons (e.g. "C:\path\file.js:10") are tolerated, matching grep-style
+  // suffixes on Windows dumps.
+  if (/^[A-Za-z]:[\\/]/.test(t)) return true;
   if (t.includes(":")) return false;
   return t.startsWith(".") || t.startsWith("/") || t.includes("/");
 }