fix: address roborev branch-review findings

Two low-severity findings from the branch review:

- releases.yml: the `verify_pypi_dependency` failure diagnostics wrapped `>=`
  in backticks inside double-quoted echo strings, so bash ran `>=` as command
  substitution — dropping `>=` from the message and creating a stray `=` file.
  Switch to single quotes with the requirement passed as a separate argument.

- core/metadata/v2.py: the "Re-export ... historical name" comment sat above
  an unrelated `parse_separator` import. Move it to the
  `ArrayV2MetadataDict = _ArrayMetadataV2` assignment it actually describes.

The third finding (pyright via uvx possibly not resolving src imports) was
verified as a non-issue: the zarr-metadata pyright CI job passes on the
current branch tip.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: d-v-b

.github/workflows/releases.yml

@@ -146,8 +146,8 @@ jobs:
             | head -1)"
 
           if [ -z "$floor" ]; then
-            echo "::error::Could not extract a `>=` floor from: $req_line"
-            echo "zarr-python's zarr-metadata requirement must include a `>=` bound so this gate has something to check."
+            echo '::error::Could not extract a >= floor from:' "$req_line"
+            echo "zarr-python's zarr-metadata requirement must include a >= bound so this gate has something to check."
             exit 1
           fi
           echo "zarr-metadata floor: $floor"

src/zarr/core/metadata/v2.py

@@ -32,8 +32,6 @@
 from zarr_metadata.v2.array import ArrayMetadataV2 as _ArrayMetadataV2
 
 from zarr.core.array_spec import ArrayConfig, ArraySpec
-
-# Re-export the v2 array metadata JSON shape under zarr-python's historical name.
 from zarr.core.chunk_key_encodings import parse_separator
 from zarr.core.common import (
     JSON,
@@ -47,6 +45,7 @@
 
 # Union of acceptable types for v2 compressors
 type CompressorLikev2 = dict[str, JSON] | Numcodec | None
+# Re-export the v2 array metadata JSON shape under zarr-python's historical name.
 ArrayV2MetadataDict = _ArrayMetadataV2