fix(core): recognise Windows backslash paths in grep_search output

core/util/grepSearch.ts

@@ -57,7 +57,9 @@ export function formatGrepSearchResults(
 
   let resultLines: string[] = [];
   for (const line of results.split("\n").filter((l) => !!l)) {
-    if (line.startsWith("./") || line === "--") {
+    // ripgrep headings start with the relative path: "./" on POSIX, ".\" on Windows.
+    // Only checking "./" silently discarded every match on Windows (#13027).
+    if (line.startsWith("./") || line.startsWith(".\\") || line === "--") {
       processResult(resultLines); // process previous result
       resultLines = [line];
       numResults++;

core/util/grepSearch.vitest.ts

@@ -215,3 +215,21 @@ test("decreases indentation when original is more than 2 spaces", () => {
   expect(result.formatted).toContain("    tooMuchIndent();");
   expect(result.formatted).toContain("  }");
 });
+
+test("parses Windows ripgrep output with backslash path separators", () => {
+  // On Windows, ripgrep emits headings like `.\dir\file.ext` instead of `./dir/file.ext`.
+  // The parser must recognise those as file headers, otherwise every match is discarded (#13027).
+  const windowsOutput = [
+    ".\\src\\program.cs",
+    '        Console.WriteLine("Hello World!");',
+    "--",
+    ".\\test\\calc.kt",
+    "    fun subtract(number: Double): Test {",
+  ].join("\n");
+
+  const result = formatGrepSearchResults(windowsOutput);
+
+  expect(result.numResults).toBeGreaterThan(0);
+  expect(result.formatted).toContain("program.cs");
+  expect(result.formatted).toContain("calc.kt");
+});