Fix missing file hashes when running on windows system (#5341)

* test: add windows unit test job and capture dir resolver path bug

- add a `Unit tests (Windows)` job running a new `make unit:windows` task, scoped to the packages that own host path handling (tests needing linux docker fixtures are skipped)
- `Unit tests` is now a gate job over the Linux and Windows unit jobs
- add a resolver test asserting that locations from `AllLocations` resolve again via `FilesByPath` and use posix paths. This is expected to fail on windows today, which is why file digests come back empty for `dir:` scans (#5325)
- fix windows-only test files that no longer compiled

Signed-off-by: Alex Goodman <wagoodman@users.noreply.github.com>

* chore: drop verbose output from integration tests

Signed-off-by: Alex Goodman <wagoodman@users.noreply.github.com>

* fix: windows path handling outside of the file lookup bug

- chroot paths are always posix (`ToChrootPath` no longer returns backslash paths on windows), same for the directory source name derived from `base`
- `windows.FromPosix` no longer panics on input that isn't volume-encoded (e.g. relative or already native paths)
- skip tests on windows that rely on symlink fixtures, shell script fixtures, or emulate windows paths on a posix host
- disable `core.autocrlf` on the windows CI job so fixture digests match linux

This leaves only the `FilesByPath` lookup failures from #5325.

Signed-off-by: Alex Goodman <wagoodman@users.noreply.github.com>

* test: skip posix-only fileresolver tests on windows

Signed-off-by: Alex Goodman <wagoodman@users.noreply.github.com>

* fix: split contained paths on posix separators on windows

- `allContainedPaths` cleaned with the native separator but split on `/`, so a root reached through a symlink never had its ancestors indexed on windows
- index assertions in tests now key on the posix path the index actually stores
- skip symlink fixture tests and a posix-only test helper on windows

Signed-off-by: Alex Goodman <wagoodman@users.noreply.github.com>

* chore: revert unrelated go.sum churn and allContainedPaths change

- restore `go.sum` and `.make/go.sum` (accidentally populated by a local `-mod=mod` invocation)
- revert the `allContainedPaths` separator change: production passes native windows paths there, and splitting them on `/` produces drive-relative ancestors, so skip the posix-only test on windows instead
- annotate the remaining `filepath` usages that operate on native paths

Signed-off-by: Alex Goodman <wagoodman@users.noreply.github.com>

* fix: search the file tree with posix paths on windows (#5325)

The directory and file resolvers key their file tree on posix paths (`/c/some/path`), but `FilesByPath`, `HasPath` and root-anchored `FilesByGlob` searched it with the native path from the chroot context (`C:\some\path`). On windows every lookup silently missed, so anything that resolves files by path found nothing. This is why file digests were empty for `dir:` scans.

Requests are now converted to posix before searching the tree.

Signed-off-by: Alex Goodman <wagoodman@users.noreply.github.com>

---------

Signed-off-by: Alex Goodman <wagoodman@users.noreply.github.com>

.github/workflows/validations.yaml

@@ -49,6 +49,13 @@ jobs:
   Unit-Test:
     # Note: changing this job name requires making the same update in the .github/workflows/release.yaml pipeline
     name: "Unit tests"
+    runs-on: ubuntu-latest
+    needs: [Unit-Test-Linux, Unit-Test-Windows]
+    steps:
+      - run: echo All unit tests passed!
+
+  Unit-Test-Linux:
+    name: "Unit tests (Linux)"
     runs-on: *test-runner
     permissions:
       contents: read
@@ -68,6 +75,27 @@ jobs:
       - name: Check for capability drift
         run: make check-capability-drift
 
+  Unit-Test-Windows:
+    name: "Unit tests (Windows)"
+    runs-on: windows-latest
+    permissions:
+      contents: read
+    steps:
+      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 #v7.0.1
+        with:
+          persist-credentials: false
+
+      # go-make's setup only (not ./.github/actions/bootstrap): no apt, binny tools, or fixture cache are needed
+      - name: Setup go + go-make tooling
+        uses: anchore/go-make/.github/actions/setup@fa5421b3bf24c9d18f11a736c5eb4172f2b7d683 # v0.8.1
+        with:
+          # keep in sync with the go-version default in ./.github/actions/bootstrap
+          go-version: "1.26.2"
+
+      # the full unit suite leans on linux docker fixtures, so this runs the windows-relevant subset
+      - name: Run unit tests
+        run: make unit:windows
+
   Integration-Test:
     # Note: changing this job name requires making the same update in the .github/workflows/release.yaml pipeline
     name: "Integration tests"