refactor(release): typed enums + __post_init__ validation on ParsedRelease

ParsedRelease accepted any string for media_type/parse_path and had no
validation on numeric ranges (season=-5 was silently accepted). Tighten
both ends:

- New str-backed Enums MediaTypeToken and ParsePath. Inherit from str so
  every existing comparison ('== "movie"'), JSON serialization, and TMDB
  DTO interop keeps working unchanged.
- ParsedRelease.__post_init__ now validates: raw/group non-empty, year in
  1888-2100, season 0-100, episode 0-9999, episode_end >= episode,
  media_type/parse_path against the enum allowlist.
- services.py uses the enum .value members everywhere instead of bare
  string literals — kills the typo risk.

alfred/domain/release/services.py

@@ -16,7 +16,9 @@ from .value_objects import (
     _RESOLUTIONS,
     _SOURCES,
     _VIDEO_META,
+    MediaTypeToken,
     ParsedRelease,
+    ParsePath,
 )
 
 
@@ -39,12 +41,12 @@ def parse_release(name: str) -> ParsedRelease:
          and run token-level matchers (season/episode, tech, languages, audio,
          video, edition, title, year).
     """
-    parse_path = "direct"
+    parse_path = ParsePath.DIRECT.value
 
     # Always try to extract a bracket-enclosed site tag first.
     clean, site_tag = _strip_site_tag(name)
     if site_tag is not None:
-        parse_path = "sanitized"
+        parse_path = ParsePath.SANITIZED.value
 
     if not _is_well_formed(clean):
         return ParsedRelease(
@@ -60,9 +62,9 @@ def parse_release(name: str) -> ParsedRelease:
             codec=None,
             group="UNKNOWN",
             tech_string="",
-            media_type="unknown",
+            media_type=MediaTypeToken.UNKNOWN.value,
             site_tag=site_tag,
-            parse_path="ai",
+            parse_path=ParsePath.AI.value,
         )
 
     name = clean
@@ -137,19 +139,19 @@ def _infer_media_type(
     integrale_tokens = {t.upper() for t in _MEDIA_TYPE_TOKENS.get("integrale", [])}
 
     if upper_tokens & doc_tokens:
-        return "documentary"
+        return MediaTypeToken.DOCUMENTARY.value
     if upper_tokens & concert_tokens:
-        return "concert"
+        return MediaTypeToken.CONCERT.value
     if (
         edition in {"COMPLETE", "INTEGRALE", "COLLECTION"}
         or upper_tokens & integrale_tokens
     ) and season is None:
-        return "tv_complete"
+        return MediaTypeToken.TV_COMPLETE.value
     if season is not None:
-        return "tv_show"
+        return MediaTypeToken.TV_SHOW.value
     if any([quality, source, codec, year]):
-        return "movie"
-    return "unknown"
+        return MediaTypeToken.MOVIE.value
+    return MediaTypeToken.UNKNOWN.value
 
 
 def _is_well_formed(name: str) -> bool:

alfred/domain/release/value_objects.py

@@ -3,7 +3,9 @@
 from __future__ import annotations
 
 from dataclasses import dataclass, field
+from enum import Enum
 
+from ..shared.exceptions import ValidationError
 from .knowledge import (
     load_audio,
     load_codecs,
@@ -50,6 +52,38 @@ def _sanitize_for_fs(text: str) -> str:
     return text.translate(_WIN_FORBIDDEN_TABLE)
 
 
+class MediaTypeToken(str, Enum):
+    """
+    Canonical values for ``ParsedRelease.media_type``.
+
+    Inherits from ``str`` so existing string-based comparisons (``== "movie"``,
+    JSON serialization, TMDB DTO interop) keep working unchanged. The enum
+    serves both as documentation and as the set of valid values for
+    ``__post_init__`` validation.
+    """
+
+    MOVIE = "movie"
+    TV_SHOW = "tv_show"
+    TV_COMPLETE = "tv_complete"
+    DOCUMENTARY = "documentary"
+    CONCERT = "concert"
+    OTHER = "other"
+    UNKNOWN = "unknown"
+
+
+class ParsePath(str, Enum):
+    """How a ``ParsedRelease`` was produced. ``str``-backed for the same
+    reasons as :class:`MediaTypeToken`."""
+
+    DIRECT = "direct"
+    SANITIZED = "sanitized"
+    AI = "ai"
+
+
+_VALID_MEDIA_TYPES: frozenset[str] = frozenset(m.value for m in MediaTypeToken)
+_VALID_PARSE_PATHS: frozenset[str] = frozenset(p.value for p in ParsePath)
+
+
 def _strip_episode_from_normalized(normalized: str) -> str:
     """
     Remove all episode parts (Exx) from a normalized release name, keeping Sxx.
@@ -85,13 +119,11 @@ class ParsedRelease:
     codec: str | None  # x265, HEVC, …
     group: str  # release group, "UNKNOWN" if missing
     tech_string: str  # quality.source.codec joined with dots
-    media_type: str = (
-        "unknown"  # "movie" | "tv_show" | "tv_complete" | "other" | "unknown"
-    )
+    media_type: str = MediaTypeToken.UNKNOWN.value  # one of MediaTypeToken values
     site_tag: str | None = (
         None  # site watermark stripped from name, e.g. "TGx", "OxTorrent.vc"
     )
-    parse_path: str = "direct"  # "direct" | "sanitized" | "ai"
+    parse_path: str = ParsePath.DIRECT.value  # one of ParsePath values
     languages: list[str] = field(default_factory=list)  # ["MULTI", "VFF"], ["FRENCH"], …
     audio_codec: str | None = None  # "DTS-HD.MA", "DDP", "EAC3", …
     audio_channels: str | None = None  # "5.1", "7.1", "2.0", …
@@ -99,6 +131,44 @@ class ParsedRelease:
     hdr_format: str | None = None  # "DV", "HDR10", "DV.HDR10", …
     edition: str | None = None  # "UNRATED", "EXTENDED", "DIRECTORS.CUT", …
 
+    def __post_init__(self) -> None:
+        if not self.raw:
+            raise ValidationError("ParsedRelease.raw cannot be empty")
+        if not self.group:
+            raise ValidationError("ParsedRelease.group cannot be empty")
+        if self.year is not None and not (1888 <= self.year <= 2100):
+            raise ValidationError(
+                f"ParsedRelease.year out of range: {self.year}"
+            )
+        if self.season is not None and not (0 <= self.season <= 100):
+            raise ValidationError(
+                f"ParsedRelease.season out of range: {self.season}"
+            )
+        if self.episode is not None and not (0 <= self.episode <= 9999):
+            raise ValidationError(
+                f"ParsedRelease.episode out of range: {self.episode}"
+            )
+        if self.episode_end is not None:
+            if not (0 <= self.episode_end <= 9999):
+                raise ValidationError(
+                    f"ParsedRelease.episode_end out of range: {self.episode_end}"
+                )
+            if self.episode is not None and self.episode_end < self.episode:
+                raise ValidationError(
+                    f"ParsedRelease.episode_end ({self.episode_end}) < "
+                    f"episode ({self.episode})"
+                )
+        if self.media_type not in _VALID_MEDIA_TYPES:
+            raise ValidationError(
+                f"ParsedRelease.media_type invalid: {self.media_type!r} "
+                f"(expected one of {sorted(_VALID_MEDIA_TYPES)})"
+            )
+        if self.parse_path not in _VALID_PARSE_PATHS:
+            raise ValidationError(
+                f"ParsedRelease.parse_path invalid: {self.parse_path!r} "
+                f"(expected one of {sorted(_VALID_PARSE_PATHS)})"
+            )
+
     @property
     def is_season_pack(self) -> bool:
         return self.season is not None and self.episode is None