Add a root action for GitHub Marketplace, and publish the docs with GitHub Pages

.github/workflows/action.yml

@@ -140,6 +140,49 @@ jobs:
           python3 -c 'from mache import match_estimate, rating_estimate'
           test "$REPORTED" = "$(python3 -c 'import mache; print(mache.__version__)')"
 
+  root:
+    # The action at the root, which the Marketplace lists, called the way a
+    # caller calls it: games already on the runner, found by a pattern, and
+    # nothing set up first. The runner's own python3 is all it needs.
+    runs-on: ubuntu-latest
+    timeout-minutes: 10
+    defaults:
+      run:
+        shell: bash
+    steps:
+      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+        with:
+          persist-credentials: false
+
+      - name: Lay the games out as two downloaded shards
+        run: |
+          for shard in 0 1; do
+            mkdir -p "downloaded/shard-${shard}"
+            cp tests/fixtures/pairs.pgn "downloaded/shard-${shard}/games.pgn"
+          done
+
+      - uses: ./ # zizmor: ignore[self-repository]
+        id: estimate
+        with:
+          pgn: downloaded/**/games.pgn
+          candidate: new
+          baseline: old
+          time_control: 10+0.1
+          sprt: true
+
+      - name: It read both shards and judged the test
+        env:
+          LINE: ${{ steps.estimate.outputs.line }}
+          VERDICT: ${{ steps.estimate.outputs.verdict }}
+          CARRIED: ${{ steps.estimate.outputs.carried }}
+        run: |
+          case "$LINE" in
+            *"(52 games), SPRT [0, 10] "*) ;;
+            *) echo "::error::the line reads ${LINE}"; exit 1 ;;
+          esac
+          test "$VERDICT" = inconclusive
+          test "$CARRIED" = 2,4,12,6,2
+
   orchestration:
     # The actions a caller runs before anything is built. Each is checked
     # through its outputs, because outputs are the part a workflow author

AGENTS.md

@@ -39,9 +39,10 @@ on it: the reusable workflows pin the actions beside them, those pins have to
 name the version being released, and `GITHUB_TOKEN` may not write under
 `.github/workflows/`, so the workflow cannot move them itself.
 `.github/workflows/README.md` says what the pins are.
-The calls shown in `examples/`, `docs/QUICKSTART.md` and
-`.github/workflows/README.md` name the same version and move in the same
-commit. `tests/test_examples.py` holds them to it.
+The calls shown in `examples/`, `docs/QUICKSTART.md`,
+`.github/workflows/README.md` and the README's call of the root action name the
+same version and move in the same commit. `tests/test_examples.py` holds them to
+it.
 Merging that pull request tags `vX.Y.Z` on
 the commit that carries the version and starts the release, which refuses a tag
 that does not match `__version__`, builds the sdist and the wheel, publishes
@@ -61,6 +62,18 @@ The `--json` shape is a contract from `0.1.0` on. `JSON_FORMAT` says which
 shape, fields are added and not removed, and a change that cannot be made that
 way raises the number.
 
+## The action at the root and the site
+
+`action.yml` at the root is the one GitHub Marketplace lists. It runs the
+package from its own checkout, so it has no pin to move. Whether a release is
+listed is set on the GitHub release itself, by its Marketplace checkbox.
+
+`docs/` is the site GitHub Pages builds, with Jekyll and the theme named in
+`docs/_config.yml`. Each page's address and place in the menu are set there
+rather than in front matter, which GitHub would show as a table when the file
+is read in the repository. A link out of `docs/` is written as a full URL,
+since the site has nothing above it. `tests/test_docs.py` checks both.
+
 ## What stays out of this repository
 
 Planning documents, unless one has been asked for. Keep them in a scratch