cache_size_bytes() does a full stat() of every file in the cache
directory. It was called on every image load and every infinite
scroll drain. Now skipped if less than 30 seconds since the last
check.
Also replace QPixmap with QImageReader in image_dimensions() to
read width/height from the file header without decoding the full
image into memory.
behavior change: cache eviction checks run at most once per 30s
instead of on every image load. Library image dimensions are read
via QImageReader (header-only) instead of QPixmap (full decode).
CI installs httpx + Pillow + pytest but not PySide6. The Phase C
tests import pure functions from controller modules, which had
top-level PySide6 imports (QTimer, QPixmap, QApplication, QMessageBox).
Move these to lazy imports inside the methods that need them so the
module-level pure functions remain importable without Qt.
Move 26 bookmark/save/library/batch/blacklist methods and _batch_dest
state into gui/post_actions.py. Rewire 8 signal connections and update
popout_controller signal targets.
Extract is_batch_message and is_in_library as pure functions for
Phase 2 tests. main_window.py: 1935 -> 1400 lines.
behavior change: none
Move 5 popout lifecycle methods (_open_fullscreen_preview,
_on_fullscreen_closed, _navigate_fullscreen, _update_fullscreen,
_update_fullscreen_state) and 4 state attributes (_fullscreen_window,
_popout_active, _info_was_visible, _right_splitter_sizes) into
gui/popout_controller.py.
Rename pass across ALL gui/ files: self._fullscreen_window ->
self._popout_ctrl.window (or self._app._popout_ctrl.window in other
controllers), self._popout_active -> self._popout_ctrl.is_active.
Zero remaining references outside popout_controller.py.
Extract build_video_sync_dict as a pure function for Phase 2 tests.
main_window.py: 2145 -> 1935 lines.
behavior change: none
Move 10 media loading methods (_on_post_activated, _on_image_done,
_on_video_stream, _on_download_progress, _set_preview_media,
_prefetch_adjacent, _on_prefetch_progress, _auto_evict_cache,
_image_dimensions) and _prefetch_pause state into
gui/media_controller.py.
Extract compute_prefetch_order as a pure function for Phase 2 tests.
Update search_controller.py cross-references to use media_ctrl.
main_window.py: 2525 -> 2114 lines.
behavior change: none
