fix(subsync): read automatic sync settings at runtime

[kernitus]

Summary

Automatic subtitle sync was using max_offset_seconds, gss, and no_fix_framerate values captured when sync.py was imported. If those settings were changed later, automatic sync would keep using the old values, needing a restart of Bazarr to get picked up.

This moves those defaults back into the function body so automatic sync reads the current settings when it runs. Explicit values passed by manual sync are left unchanged.

This fixes the automatic sync settings affected by this import-time default issue:

• Max Offset Seconds
• Golden-Section Search
• Do Not Fix Framerate Mismatch

This does not change every sync-related option. For example, force_audio ("Always use Audio Track as Reference for Syncing") is already read later in SubSyncer.sync(), so it is not part of this fix.

This is the same class of bug fixed by #2414 for #2413. It appears to have been reintroduced in f5d6721 when job manager support was added to subtitle sync.

#2449 is related because the reported behaviour there, automatic sync ignoring the configured Golden-Section Search value while manual sync works, follows from the same import-time default issue.

Test plan

$ uv run --python 3.10 --with pytest --with 'setuptools<81' --with pillow --with numpy python -m pytest tests/bazarr/test_subtitles_sync.py
================================================= test session starts =================================================
platform linux -- Python 3.10.20, pytest-9.0.3, pluggy-1.6.0
Conflicting packages detected:
['pygments', 'tomli', 'zipp', 'platformdirs']
rootdir: <repo>
collected 2 items

tests/bazarr/test_subtitles_sync.py ..                                                                          [100%]

================================================== warnings summary ===================================================
tests/conftest.py:6
  <repo>/tests/conftest.py:6: UserWarning: pkg_resources is deprecated as an API. See https://setuptools.pypa.io/en/latest/pkg_resources.html. The pkg_resources package is slated for removal as early as 2025-11-30. Refrain from using this package or pin to Setuptools<81.
    import pkg_resources

bazarr/app/database.py:114
  <repo>/tests/../bazarr/app/database.py:114: MovedIn20Warning: The ``declarative_base()`` function is now available as sqlalchemy.orm.declarative_base(). (deprecated since: 2.0) (Background on SQLAlchemy 2.0 at: https://sqlalche.me/e/b8d9)
    Base = declarative_base()

-- Docs: https://docs.pytest.org/en/stable/how-to/capture-warnings.html
============================================ 2 passed, 2 warnings in 1.88s ============================================

$ uv run --python 3.11 --with pytest --with 'setuptools<81' --with pillow --with numpy python -m pytest tests/bazarr/test_subtitles_sync.py
Installed 8 packages in 17ms
================================================= test session starts =================================================
platform linux -- Python 3.11.15, pytest-9.0.3, pluggy-1.6.0
Conflicting packages detected:
['tomli', 'platformdirs', 'zipp', 'pygments']
rootdir: <repo>
collected 2 items

tests/bazarr/test_subtitles_sync.py ..                                                                          [100%]

================================================== warnings summary ===================================================
tests/conftest.py:6
  <repo>/tests/conftest.py:6: UserWarning: pkg_resources is deprecated as an API. See https://setuptools.pypa.io/en/latest/pkg_resources.html. The pkg_resources package is slated for removal as early as 2025-11-30. Refrain from using this package or pin to Setuptools<81.
    import pkg_resources

bazarr/app/database.py:114
  <repo>/tests/../bazarr/app/database.py:114: MovedIn20Warning: The ``declarative_base()`` function is now available as sqlalchemy.orm.declarative_base(). (deprecated since: 2.0) (Background on SQLAlchemy 2.0 at: https://sqlalche.me/e/b8d9)
    Base = declarative_base()

-- Docs: https://docs.pytest.org/en/stable/how-to/capture-warnings.html
============================================ 2 passed, 2 warnings in 3.58s ============================================

$ uv run --python 3.12 --with pytest --with 'setuptools<81' --with pillow --with numpy python -m pytest tests/bazarr/test_subtitles_sync.py
Installed 8 packages in 10ms
================================================= test session starts =================================================
platform linux -- Python 3.12.9, pytest-9.0.3, pluggy-1.6.0
Conflicting packages detected:
['tomli', 'platformdirs', 'zipp', 'pygments']
rootdir: <repo>
collected 2 items

tests/bazarr/test_subtitles_sync.py ..                                                                          [100%]

================================================== warnings summary ===================================================
tests/conftest.py:6
  <repo>/tests/conftest.py:6: UserWarning: pkg_resources is deprecated as an API. See https://setuptools.pypa.io/en/latest/pkg_resources.html. The pkg_resources package is slated for removal as early as 2025-11-30. Refrain from using this package or pin to Setuptools<81.
    import pkg_resources

custom_libs/subliminal/refiners/tvdb.py:66
  <repo>/tests/../custom_libs/subliminal/refiners/tvdb.py:66: DeprecationWarning: datetime.datetime.utcnow() is deprecated and scheduled for removal in a future version. Use timezone-aware objects to represent datetimes in UTC: datetime.datetime.now(datetime.UTC).
    self.token_date = datetime.utcnow() - self.token_lifespan

bazarr/app/database.py:114
  <repo>/tests/../bazarr/app/database.py:114: MovedIn20Warning: The ``declarative_base()`` function is now available as sqlalchemy.orm.declarative_base(). (deprecated since: 2.0) (Background on SQLAlchemy 2.0 at: https://sqlalche.me/e/b8d9)
    Base = declarative_base()

-- Docs: https://docs.pytest.org/en/stable/how-to/capture-warnings.html
============================================ 2 passed, 3 warnings in 3.73s ============================================

$ uv run --python 3.13 --with pytest --with 'setuptools<81' --with pillow --with numpy python -m pytest tests/bazarr/test_subtitles_sync.py
================================================= test session starts =================================================
platform linux -- Python 3.13.13, pytest-9.0.3, pluggy-1.6.0
Conflicting packages detected:
['pygments', 'zipp', 'tomli', 'platformdirs']
rootdir: <repo>
collected 2 items

tests/bazarr/test_subtitles_sync.py ..                                                                          [100%]

================================================== warnings summary ===================================================
tests/conftest.py:6
  <repo>/tests/conftest.py:6: UserWarning: pkg_resources is deprecated as an API. See https://setuptools.pypa.io/en/latest/pkg_resources.html. The pkg_resources package is slated for removal as early as 2025-11-30. Refrain from using this package or pin to Setuptools<81.
    import pkg_resources

custom_libs/subliminal/refiners/tvdb.py:66
  <repo>/tests/../custom_libs/subliminal/refiners/tvdb.py:66: DeprecationWarning: datetime.datetime.utcnow() is deprecated and scheduled for removal in a future version. Use timezone-aware objects to represent datetimes in UTC: datetime.datetime.now(datetime.UTC).
    self.token_date = datetime.utcnow() - self.token_lifespan

bazarr/app/database.py:114
  <repo>/tests/../bazarr/app/database.py:114: MovedIn20Warning: The ``declarative_base()`` function is now available as sqlalchemy.orm.declarative_base(). (deprecated since: 2.0) (Background on SQLAlchemy 2.0 at: https://sqlalche.me/e/b8d9)
    Base = declarative_base()

-- Docs: https://docs.pytest.org/en/stable/how-to/capture-warnings.html
============================================ 2 passed, 3 warnings in 1.42s ============================================

Notes:

• I installed setuptools<81 in the disposable test container because the current test harness imports pkg_resources from tests/conftest.py, and it looks like the dev container has setuptools 82.0.1 where that import doesn't seem to work.
• Couldn't run the full suite of tests even inside the Docker container, seems to require a lot of dependencies and setup I couldn't get working easily

Manual testing

Tested inside the provided Dev docker container (which is Python 3.12)

[morpheus65535]

Thanks!