chore: sprint cleanup — language unification, parser unification, fossils removal

Several weeks of work accumulated without being committed. Grouped here for
clarity; see CHANGELOG.md [Unreleased] for the user-facing summary.

Highlights
----------

P1 #2 — ISO 639-2/B canonical migration
- New Language VO + LanguageRegistry (alfred/domain/shared/knowledge/).
- iso_languages.yaml as single source of truth for language codes.
- SubtitleKnowledgeBase now delegates lookup to LanguageRegistry; subtitles.yaml
  only declares subtitle-specific tokens (vostfr, vf, vff, …).
- SubtitlePreferences default → ["fre", "eng"]; subtitle filenames written as
  {iso639_2b}.srt (legacy fr.srt still read via alias).
- Scanner: dropped _LANG_KEYWORDS / _SDH_TOKENS / _FORCED_TOKENS /
  SUBTITLE_EXTENSIONS hardcoded dicts.
- Fixed: 'hi' token no longer marks SDH (conflicted with Hindi alias).
- Added settings.min_movie_size_bytes (was a module constant).

P1 #3 — Release parser unification + data-driven tokenizer
- parse_release() is now the single source of truth for release-name parsing.
- alfred/knowledge/release/separators.yaml declares the token separators used
  by the tokenizer (., space, [, ], (, ), _). New conventions can be added
  without code changes.
- Tokenizer now splits on any configured separator instead of name.split('.').
  Releases like 'The Father (2020) [1080p] [WEBRip] [5.1] [YTS.MX]' parse via
  the direct path without sanitization fallback.
- Site-tag extraction always runs first; well-formedness only rejects truly
  forbidden chars.
- _parse_season_episode() extended with NxNN / NxNNxNN alt forms.
- Removed dead helpers: _sanitize, _normalize.

Domain cleanup
- Deleted fossil services with zero production callers:
    alfred/domain/movies/services.py
    alfred/domain/tv_shows/services.py
    alfred/domain/subtitles/services.py (replaced by subtitles/services/ package)
    alfred/domain/subtitles/repositories.py
- Split monolithic subtitle services into a package (identifier, matcher,
  placer, pattern_detector, utils) + dedicated knowledge/ package.
- MediaInfo split into dedicated package (alfred/domain/shared/media/:
  audio, video, subtitle, info, matching).

Persistence cleanup
- Removed dead JSON repositories (movie/subtitle/tvshow_repository.py).

Tests
- Major expansion of the test suite organized to mirror the source tree.
- Removed obsolete *_edge_cases test files superseded by structured tests.
- Suite: 990 passed, 8 skipped.

Misc
- .gitignore: exclude env_backup/ and *.bak.
- Adjustments across agent/llm, app.py, application/filesystem, and
  infrastructure/filesystem to align with the new domain layout.

alfred/application/filesystem/enrich_from_probe.py

@@ -3,7 +3,7 @@
 from __future__ import annotations
 
 from alfred.domain.release.value_objects import ParsedRelease
-from alfred.domain.shared.media_info import MediaInfo
+from alfred.domain.shared.media import MediaInfo
 
 # Map ffprobe codec names to scene-style codec tokens
 _VIDEO_CODEC_MAP = {

alfred/application/filesystem/manage_subtitles.py

@@ -4,7 +4,7 @@ import logging
 from pathlib import Path
 
 from alfred.domain.shared.value_objects import ImdbId
-from alfred.domain.subtitles.entities import SubtitleTrack
+from alfred.domain.subtitles.entities import SubtitleCandidate
 from alfred.domain.subtitles.knowledge.base import SubtitleKnowledgeBase
 from alfred.domain.subtitles.knowledge.loader import KnowledgeLoader
 from alfred.domain.subtitles.services.identifier import SubtitleIdentifier
@@ -264,7 +264,7 @@ class ManageSubtitlesUseCase:
 
 
 def _to_unresolved_dto(
-    track: SubtitleTrack, min_confidence: float = 0.7
+    track: SubtitleCandidate, min_confidence: float = 0.7
 ) -> UnresolvedTrack:
     reason = "unknown_language" if track.language is None else "low_confidence"
     return UnresolvedTrack(
@@ -277,10 +277,10 @@ def _to_unresolved_dto(
 
 def _pair_placed_with_tracks(
     placed: list[PlacedTrack],
-    tracks: list[SubtitleTrack],
-) -> list[tuple[PlacedTrack, SubtitleTrack]]:
+    tracks: list[SubtitleCandidate],
+) -> list[tuple[PlacedTrack, SubtitleCandidate]]:
     """
-    Pair each PlacedTrack with its originating SubtitleTrack by source path.
+    Pair each PlacedTrack with its originating SubtitleCandidate by source path.
     Falls back to positional matching if paths don't align.
     """
     track_by_path = {t.file_path: t for t in tracks if t.file_path}