fix: review cleanup — imports, _FakeToken, use_spacy_segmentation

- Move pronunciation imports from inside run() to top-level imports
- Extract _FakeToken to module level (was redefined every loop iteration)
- use_spacy_segmentation now mirrors PyQt logic: pass the flag,
  let process_subtitle_tokens filter by language internally

abogen/pyqt/conversion.py

@@ -39,6 +39,11 @@ from abogen.domain.subtitle_generation import process_subtitle_tokens
 from abogen.domain.voice_loader import load_voice_cached
 from abogen.domain.progress import calc_etr_str
 from abogen.domain.normalization import prepare_text_for_tts
+from abogen.domain.pronunciation import (
+    compile_pronunciation_rules,
+    compile_heteronym_sentence_rules,
+    merge_pronunciation_overrides,
+)
 from abogen.domain.metadata_extraction import (
     extract_metadata_and_build_args,
     read_text_for_metadata,
@@ -537,11 +542,6 @@ class ConversionThread(QThread):
                 )
 
             # --- Compile normalization rules (heteronym + pronunciation) ---
-            from abogen.domain.pronunciation import (
-                compile_pronunciation_rules,
-                compile_heteronym_sentence_rules,
-                merge_pronunciation_overrides,
-            )
             pronunciation_overrides = merge_pronunciation_overrides(
                 getattr(self, "pronunciation_overrides", None),
                 getattr(self, "manual_overrides", None),