GRM-51: refactor: convert shell scripts and inline workflow scripts to Python

scripts/ci/distribute_molecule.py

@@ -100,6 +100,17 @@ def pairs_for_runner(pairs: list[TestPair], runner_index: int, max_runners: int)
     return groups[runner_index]
 
 
+def _write_github_env(key: str, value: str) -> None:
+    """Append a key=value line to the $GITHUB_ENV file."""
+    import os
+
+    gh_env = os.environ.get("GITHUB_ENV")
+    if not gh_env:
+        raise click.ClickException("GITHUB_ENV environment variable is not set")
+    with open(gh_env, "a") as f:  # noqa: PTH123
+        f.write(f"{key}={value}\n")
+
+
 @click.command()
 @click.option(
     "--runner-index",
@@ -127,7 +138,27 @@ def pairs_for_runner(pairs: list[TestPair], runner_index: int, max_runners: int)
     is_flag=True,
     help="List all supported platforms, one per line.",
 )
-def cli(runner_index: int | None, max_runners: int, list_all: bool, list_platforms: bool) -> None:
+@click.option(
+    "--github-env",
+    "github_env",
+    is_flag=True,
+    default=False,
+    help="Write TEST_PAIRS and SKIP to $GITHUB_ENV (for CI workflow steps).",
+)
+@click.option(
+    "--skip-if-excess",
+    is_flag=True,
+    default=False,
+    help="With --github-env: write SKIP=true when runner-index exceeds max-runners.",
+)
+def cli(
+    runner_index: int | None,
+    max_runners: int,
+    list_all: bool,
+    list_platforms: bool,
+    github_env: bool,
+    skip_if_excess: bool,
+) -> None:
     scenarios = discover_scenarios()
     if list_all:
         for s in scenarios:
@@ -144,10 +175,26 @@ def cli(runner_index: int | None, max_runners: int, list_all: bool, list_platfor
             labels = " ".join(p.encode() for p in group) if group else "(none)"
             click.echo(f"Runner {i}: {labels}")
         return
+
+    # Skip if runner index exceeds available runners (CI static matrix has 3 slots)
+    if skip_if_excess and github_env and runner_index > max_runners:
+        click.echo(f"Skipping — runner index {runner_index} > max runners {max_runners}")
+        _write_github_env("TEST_PAIRS", "")
+        _write_github_env("SKIP", "true")
+        return
+
     # Convert 1-based CLI index to 0-based internal index
     zero_based = runner_index - 1
     assigned = pairs_for_runner(pairs, zero_based, max_runners)
-    click.echo(" ".join(p.encode() for p in assigned))
+    encoded = " ".join(p.encode() for p in assigned)
+
+    if github_env:
+        _write_github_env("TEST_PAIRS", encoded)
+        _write_github_env("SKIP", "false")
+        click.echo(f"Assigned pairs: {encoded}")
+        return
+
+    click.echo(encoded)
 
 
 if __name__ == "__main__":  # pragma: no cover