fix(tests): canonicalize expected writer filepath on Windows (#238)

* fix(tests): canonicalize expected writer filepath on Windows

build_pipeline_outputs canonicalizes output paths to forward slashes on
every platform, but the execution-map writer test built its expectation
from str(tmp_path), which yields backslashes on Windows — failing there
while ubuntu CI stayed green. Normalize the expected prefix the same way
test_easy_ai_pipeline.py already does. No-op on POSIX.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* ci: run pytest job on a windows-latest matrix lane

The suite is now Windows-clean (previous commit), but only ubuntu ran in
CI - the path-separator regression this PR fixes was invisible until a
local Windows run. Add windows-latest to the pytest job so that class of
break gates PRs. fail-fast off so a Windows-only failure still reports
alongside the green ubuntu lane.

Safe rename: Protect-main requires only "Lint & Smoke" and "Security
Gate", so Pytest -> "Pytest (os)" breaks no required check.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

---------

Co-authored-by: Claude Fable 5 <noreply@anthropic.com>

.github/workflows/ci.yml

@@ -71,7 +71,14 @@ jobs:
 
   pytest:
     name: Pytest
-    runs-on: ubuntu-latest
+    runs-on: ${{ matrix.os }}
+    strategy:
+      # Keep both lanes reporting even when one fails — a Windows-only
+      # failure with a green ubuntu lane is exactly the signal this
+      # matrix exists to surface.
+      fail-fast: false
+      matrix:
+        os: [ubuntu-latest, windows-latest]
     steps:
       - uses: actions/checkout@v4