refactor: move UV index config into pre-commit hook

Make uv-lock pre-commit hook smart about release branches by wrapping it
in a script that detects release branches and sets UV_EXTRA_INDEX_URL.

This allows the same pre-commit config to work locally and in CI without
special environment variable setup in workflows.

Changes:
- Add scripts/pre-commit-uv-lock.sh wrapper that detects release branches
- Move uv-lock from astral-sh/uv-pre-commit to local hook using wrapper
- Remove UV env var setup from pre-commit workflow (hook handles it)
- Regenerate uv.lock with test.pypi as extra index (not primary)

scripts/pre-commit-uv-lock.sh

@@ -0,0 +1,22 @@
+#!/bin/bash
+# Copyright (c) Meta Platforms, Inc. and affiliates.
+# All rights reserved.
+#
+# This source code is licensed under the terms described in the LICENSE file in
+# the root directory of this source tree.
+
+set -euo pipefail
+
+# Detect current branch
+BRANCH=$(git rev-parse --abbrev-ref HEAD 2>/dev/null || echo "")
+
+# On release branches, use test.pypi as extra index for RC versions
+if [[ "$BRANCH" =~ ^release-[0-9]+\.[0-9]+\.x$ ]]; then
+  echo "Detected release branch: $BRANCH"
+  echo "Setting UV_EXTRA_INDEX_URL=https://test.pypi.org/simple/"
+  export UV_EXTRA_INDEX_URL="https://test.pypi.org/simple/"
+  export UV_INDEX_STRATEGY="unsafe-best-match"
+fi
+
+# Run uv lock
+exec uv lock "$@"