Please address the comments from this code review:

## Overall Comments
- requests is now a required dependency but could be made optional under the musicbrainz extra to avoid imposing it on users who don't need the plugin.
- With the removal of MusicBrainzAPIError, HTTP errors will surface as raw exceptions without context; consider wrapping these to include the entity and query for clearer error messages.
- TimeoutSession registers an atexit callback each time it’s instantiated; to prevent multiple registrations you might move the close handler to module scope or guard against duplicates.

## Individual Comments

### Comment 1
<location> `beetsplug/musicbrainz.py:125` </location>
<code_context>
+    def browse_recordings(self, **kwargs) -> list[JSONDict]:
+        kwargs.setdefault("limit", BROWSE_CHUNKSIZE)
+        kwargs.setdefault("inc", BROWSE_INCLUDES)
+        return self._get("recording", **kwargs)["recordings"]
+
+
</code_context>

<issue_to_address>
**suggestion:** Assumes 'recordings' key is always present in API response.

Using .get("recordings", []) will prevent KeyError if the response structure changes or an error occurs.

```suggestion
        return self._get("recording", **kwargs).get("recordings", [])
```
</issue_to_address>

### Comment 2
<location> `beetsplug/musicbrainz.py:270` </location>
<code_context>

     for country in preferred_countries:
-        for event in release.get("release-event-list", {}):
+        for event in release.get("release-events", {}):
             try:
-                if country in event["area"]["iso-3166-1-code-list"]:
</code_context>

<issue_to_address>
**issue (bug_risk):** Iterating over release-events with a default of {} may cause issues.

Use [] as the default value to ensure safe iteration and prevent TypeError if 'release-events' is missing.
</issue_to_address>

### Comment 3
<location> `beetsplug/musicbrainz.py:523-526` </location>
<code_context>
-            for medium in release["medium-list"]:
-                for recording in medium["track-list"]:
+            for medium in release["media"]:
+                for recording in medium["tracks"]:
                     recording_info = track_map[recording["recording"]["id"]]
                     recording["recording"] = recording_info
</code_context>

<issue_to_address>
**suggestion:** Assumes all 'tracks' entries have a 'recording' key.

Using recording['recording'] without checking may cause a KeyError if the key is missing. Use recording.get('recording') and handle cases where it is absent.

```suggestion
            for medium in release["media"]:
                for recording in medium["tracks"]:
                    rec = recording.get("recording")
                    if rec is not None and "id" in rec:
                        recording_info = track_map[rec["id"]]
                        recording["recording"] = recording_info
```
</issue_to_address>

### Comment 4
<location> `beetsplug/musicbrainz.py:716-719` </location>
<code_context>

             for source, url in product(wanted_sources, url_rels):
-                if f"{source}.com" in (target := url["target"]):
+                if f"{source}.com" in (target := url["url"]["resource"]):
                     urls[source] = target
                     self._log.debug(
</code_context>

<issue_to_address>
**suggestion (bug_risk):** Assumes 'url' and 'resource' keys are always present in streaming relations.

Using .get() for 'url' and 'resource' can prevent KeyErrors if these keys are missing.

```suggestion
            for source, url in product(wanted_sources, url_rels):
                target = url.get("url", {}).get("resource")
                if target and f"{source}.com" in target:
                    urls[source] = target
                    self._log.debug(
```
</issue_to_address>

### Comment 5
<location> `beetsplug/_utils/requests.py:16-18` </location>
<code_context>
+class TimeoutSession(requests.Session):
+    def __init__(self, *args, **kwargs) -> None:
+        super().__init__(*args, **kwargs)
+        beets_version = importlib.metadata.version("beets")
+        self.headers["User-Agent"] = f"beets/{beets_version} https://beets.io/"
+
</code_context>

<issue_to_address>
**suggestion:** Using importlib.metadata.version may raise PackageNotFoundError if 'beets' is not installed as a package.

If 'beets' might not be installed as a package, handle PackageNotFoundError and set a default version string.

```suggestion
import importlib.metadata

class TimeoutSession(requests.Session):
    def __init__(self, *args, **kwargs) -> None:
        super().__init__(*args, **kwargs)
        try:
            beets_version = importlib.metadata.version("beets")
        except importlib.metadata.PackageNotFoundError:
            beets_version = "unknown"
        self.headers["User-Agent"] = f"beets/{beets_version} https://beets.io/"
```
</issue_to_address>

### Comment 6
<location> `beetsplug/musicbrainz.py:652-655` </location>
<code_context>
        if "secondary-types" in release["release-group"]:
            if release["release-group"]["secondary-types"]:
                for sec_type in release["release-group"]["secondary-types"]:
                    albumtypes.append(sec_type.lower())

</code_context>

<issue_to_address>
**suggestion (code-quality):** Merge nested if conditions ([`merge-nested-ifs`](https://docs.sourcery.ai/Reference/Rules-and-In-Line-Suggestions/Python/Default-Rules/merge-nested-ifs))

```suggestion
        if "secondary-types" in release["release-group"] and release["release-group"]["secondary-types"]:
            for sec_type in release["release-group"]["secondary-types"]:
                albumtypes.append(sec_type.lower())

```

<br/><details><summary>Explanation</summary>Too much nesting can make code difficult to understand, and this is especially
true in Python, where there are no brackets to help out with the delineation of
different nesting levels.

Reading deeply nested code is confusing, since you have to keep track of which
conditions relate to which levels. We therefore strive to reduce nesting where
possible, and the situation where two `if` conditions can be combined using
`and` is an easy win.
</details>
</issue_to_address>

### Comment 7
<location> `beetsplug/musicbrainz.py:177-180` </location>
<code_context>
def _multi_artist_credit(
    credit: list[JSONDict], include_join_phrase: bool
) -> tuple[list[str], list[str], list[str]]:
    """Given a list representing an ``artist-credit`` block, accumulate
    data into a triple of joined artist name lists: canonical, sort, and
    credit.
    """
    artist_parts = []
    artist_sort_parts = []
    artist_credit_parts = []
    for el in credit:
        alias = _preferred_alias(el["artist"].get("aliases", ()))

        # An artist.
        if alias:
            cur_artist_name = alias["name"]
        else:
            cur_artist_name = el["artist"]["name"]
        artist_parts.append(cur_artist_name)

        # Artist sort name.
        if alias:
            artist_sort_parts.append(alias["sort-name"])
        elif "sort-name" in el["artist"]:
            artist_sort_parts.append(el["artist"]["sort-name"])
        else:
            artist_sort_parts.append(cur_artist_name)

        # Artist credit.
        if "name" in el:
            artist_credit_parts.append(el["name"])
        else:
            artist_credit_parts.append(cur_artist_name)

        if include_join_phrase and (joinphrase := el.get("joinphrase")):
            artist_parts.append(joinphrase)
            artist_sort_parts.append(joinphrase)
            artist_credit_parts.append(joinphrase)

    return (
        artist_parts,
        artist_sort_parts,
        artist_credit_parts,
    )

</code_context>

<issue_to_address>
**suggestion (code-quality):** Replace if statement with if expression ([`assign-if-exp`](https://docs.sourcery.ai/Reference/Default-Rules/refactorings/assign-if-exp/))

```suggestion
        cur_artist_name = alias["name"] if alias else el["artist"]["name"]
```
</issue_to_address>

### Comment 8
<location> `beetsplug/musicbrainz.py:271-275` </location>
<code_context>
def _preferred_release_event(
    release: dict[str, Any],
) -> tuple[str | None, str | None]:
    """Given a release, select and return the user's preferred release
    event as a tuple of (country, release_date). Fall back to the
    default release event if a preferred event is not found.
    """
    preferred_countries: Sequence[str] = config["match"]["preferred"][
        "countries"
    ].as_str_seq()

    for country in preferred_countries:
        for event in release.get("release-events", {}):
            try:
                if country in event["area"]["iso-3166-1-codes"]:
                    return country, event["date"]
            except KeyError:
                pass

    return release.get("country"), release.get("date")

</code_context>

<issue_to_address>
**issue (code-quality):** Use `contextlib`'s `suppress` method to silence an error ([`use-contextlib-suppress`](https://docs.sourcery.ai/Reference/Default-Rules/refactorings/use-contextlib-suppress/))
</issue_to_address>