fix(release-exposure): match backslash-relative Go flag paths

GO_FLAG_PATH accepted dot-relative roots only with a forward slash, so
`-I..\sdk\include` and `-I.\sdk` produced no path and go.build_paths came
back not_observed. Accept either separator after the dots.

The CLI acceptance test now expects unknown for electron.run_as_node on a
directory with no native images, matching the service.

src/application/releaseExposure/ReleaseExposureService.test.ts

@@ -1019,7 +1019,7 @@ describe("ReleaseExposureService cleanup", () => {
   });
 });
 
-describe("ReleaseExposureService Go UNC paths", () => {
+describe("ReleaseExposureService Go Windows paths", () => {
   it("reports UNC roots retained in Go flags", async () => {
     const module = (value: string) => ({
       path: "github.com/acme/app",
@@ -1045,6 +1045,25 @@ describe("ReleaseExposureService Go UNC paths", () => {
       await goStatus(module(String.raw`-DNAME=\\ -DHOST=\\buildhost`)),
     ).toBe("not_observed");
   });
+
+  it.each([
+    [String.raw`-I..\sdk\include`, String.raw`..\sdk\include`],
+    [String.raw`-O2 -I.\sdk`, String.raw`.\sdk`],
+    [String.raw`"-isystem ..\my sdk\include"`, String.raw`..\my sdk\include`],
+  ])("reports the backslash-relative path in %s", async (value, path) => {
+    const report = await goReport({
+      path: "github.com/acme/app",
+      main: null,
+      dependencies: [],
+      settings: [{ key: "CGO_CFLAGS", value }],
+      unparsed_lines: [],
+      unparsed_line_bytes_base64: [],
+      complete: true,
+    });
+    const check = report.checks.find((item) => item.id === "go.build_paths");
+    expect(check?.status).toBe("exposed");
+    expect(check?.observation.samples).toEqual([path]);
+  });
 });
 
 describe("ReleaseExposureService Go paths", () => {

src/application/releaseExposure/ReleaseExposureService.ts

@@ -740,7 +740,7 @@ const GO_FLAG_SETTING =
 const GO_FLAG_FIELD = /(?:[^\s"']|"[^"]*"|'[^']*')+/gu;
 /** A path after a flag prefix, whitespace, `=`, or `,`, as in `-isystem/opt/x`. */
 const GO_FLAG_PATH =
-  /(?:^|[\s=,])(?:-(?:idirafter|imacros|include|iprefix|iquote|isysroot|isystem|[BFILT]))?((?:\.{1,2}\/|\/|[A-Za-z]:[\\/]|\\{2}[^\\\s=,]+\\)[^=,]+)/gu;
+  /(?:^|[\s=,])(?:-(?:idirafter|imacros|include|iprefix|iquote|isysroot|isystem|[BFILT]))?((?:\.{1,2}[\\/]|\/|[A-Za-z]:[\\/]|\\{2}[^\\\s=,]+\\)[^=,]+)/gu;
 
 /** Paths in one flag value, with a quoted path kept whole up to the next flag. */
 const goFlagPaths = (value: string): string[] =>

tests/acceptance/releaseExposureCli.test.ts

@@ -44,7 +44,7 @@ cliTest(
     expect(
       report.checks.find((check) => check.id === "electron.run_as_node")
         ?.status,
-    ).toBe("not_applicable");
+    ).toBe("unknown");
     expect(
       report.checks.find((check) => check.id === "native.pdb_path")?.status,
     ).toBe("not_applicable");