test: add real-world release fixtures (EASY bucket)

Captures 5 canonical releases from /mnt/testipool/downloads as parametrized
fixtures under tests/fixtures/releases/easy/. Each fixture declares the
release name, expected ParsedRelease fields, original tree, and the future
routing (library / torrents / seed_hardlinks) for the upcoming organize_media
refactor.

Today only the 'parsed' section is asserted; tree is materialized into a
tmp_path to catch typos. Routing is captured ahead of the planner work — it
becomes verifiable once organize_media lands.

Cases: back_in_action (movie), slow_horses_single_ep (TV single),
foundation_season_pack (S02 + .nfo noise), long_walk_with_noise (movie +
KONTRAST.TOP.txt), sinners_yts (YTS bracket-heavy + Subs/ dir).

Also tracks CHANGELOG.md under [Unreleased] / Added.

tests/domain/test_release_fixtures.py

@@ -0,0 +1,54 @@
+"""Real-world release fixtures — anti-regression baseline for parse_release.
+
+Each fixture under ``tests/fixtures/releases/<bucket>/<case>/expected.yaml``
+declares a release name and the ``ParsedRelease`` fields it should produce.
+Fields absent from the fixture's ``parsed`` block are not checked, so adding
+new attributes to ``ParsedRelease`` never breaks existing fixtures.
+
+The fixture's ``tree`` is materialized into a temp dir to prove the layout is
+self-consistent, even though no filesystem assertions are made yet. The
+``routing`` block (library / torrents / seed_hardlinks) is captured ahead of
+the ``organize_media`` refactor — it will become verifiable once the planner
+exists.
+"""
+
+from __future__ import annotations
+
+from dataclasses import asdict
+
+import pytest
+
+from alfred.domain.release.services import parse_release
+from tests.fixtures.releases.conftest import ReleaseFixture, discover_fixtures
+
+FIXTURES = discover_fixtures()
+
+
+@pytest.mark.parametrize(
+    "fixture",
+    FIXTURES,
+    ids=[f.name for f in FIXTURES],
+)
+def test_parse_matches_fixture(fixture: ReleaseFixture, tmp_path) -> None:
+    # Materialize the tree to assert it is at least well-formed YAML +
+    # plausible filesystem paths. Catches typos / missing leading dirs early.
+    fixture.materialize(tmp_path)
+
+    result = asdict(parse_release(fixture.release_name))
+    # ``is_season_pack`` is a @property — asdict() does not include it.
+    result["is_season_pack"] = parse_release(fixture.release_name).is_season_pack
+
+    for field, expected in fixture.expected_parsed.items():
+        assert field in result, (
+            f"{fixture.name}: unknown field '{field}' in expected.parsed"
+        )
+        assert result[field] == expected, (
+            f"{fixture.name}: parsed.{field} — "
+            f"expected {expected!r}, got {result[field]!r}"
+        )
+
+
+def test_at_least_one_fixture_per_bucket() -> None:
+    """Each bucket should hold at least one case once populated."""
+    buckets = {f.name.split("/")[0] for f in FIXTURES}
+    assert "easy" in buckets, "EASY bucket must have at least one fixture"