refactor(knowledge): extract YAML loaders from domain to infrastructure

The domain layer no longer reads YAML files. All knowledge loaders move
from `alfred/domain/*/knowledge/` to `alfred/infrastructure/knowledge/`:

  domain/release/knowledge.py
    → infrastructure/knowledge/release.py
  domain/shared/knowledge/language_registry.py
    → infrastructure/knowledge/language_registry.py
  domain/subtitles/knowledge/{loader,base}.py
    → infrastructure/knowledge/subtitles/{loader,base}.py

Callers in domain/release/{services,value_objects}.py,
domain/subtitles/{aggregates,services/*}.py, and
application/filesystem/manage_subtitles.py updated to absolute imports.
Re-exports of KnowledgeLoader/SubtitleKnowledgeBase from
domain/subtitles/__init__.py dropped (no shim per project convention).
Tests follow the moved targets.

tests/domain/test_subtitle_identifier.py

@@ -23,7 +23,7 @@ from unittest.mock import patch
 import pytest
 
 from alfred.domain.subtitles.entities import SubtitleCandidate
-from alfred.domain.subtitles.knowledge.base import SubtitleKnowledgeBase
+from alfred.infrastructure.knowledge.subtitles.base import SubtitleKnowledgeBase
 from alfred.domain.subtitles.services.identifier import (
     SubtitleIdentifier,
     _count_entries,

tests/domain/test_subtitle_knowledge.py

@@ -1,4 +1,4 @@
-"""Tests for ``alfred.domain.subtitles.knowledge`` (loader + base).
+"""Tests for ``alfred.infrastructure.knowledge.subtitles`` (loader + base).
 
 Covers:
 
@@ -19,9 +19,9 @@ from pathlib import Path
 
 import pytest
 
-from alfred.domain.subtitles.knowledge import loader as loader_mod
-from alfred.domain.subtitles.knowledge.base import SubtitleKnowledgeBase
-from alfred.domain.subtitles.knowledge.loader import KnowledgeLoader, _merge
+from alfred.infrastructure.knowledge.subtitles import loader as loader_mod
+from alfred.infrastructure.knowledge.subtitles.base import SubtitleKnowledgeBase
+from alfred.infrastructure.knowledge.subtitles.loader import KnowledgeLoader, _merge
 from alfred.domain.subtitles.value_objects import (
     ScanStrategy,
     SubtitleType,

tests/domain/test_subtitle_pattern_detector.py

@@ -25,7 +25,7 @@ from unittest.mock import patch
 
 import pytest
 
-from alfred.domain.subtitles.knowledge.base import SubtitleKnowledgeBase
+from alfred.infrastructure.knowledge.subtitles.base import SubtitleKnowledgeBase
 from alfred.domain.subtitles.services.pattern_detector import PatternDetector