fix: move PySide6 imports to lazy in controllers for CI compat

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.

booru_viewer/gui/media_controller.py

@@ -7,8 +7,6 @@ import logging
 from pathlib import Path
 from typing import TYPE_CHECKING
 
-from PySide6.QtGui import QPixmap
-
 from ..core.cache import download_image, cache_size_bytes, evict_oldest, evict_oldest_thumbnails
 
 if TYPE_CHECKING:
@@ -265,6 +263,7 @@ class MediaController:
         if _is_video(path):
             return 0, 0
         try:
+            from PySide6.QtGui import QPixmap
             pix = QPixmap(path)
             if not pix.isNull():
                 return pix.width(), pix.height()

booru_viewer/gui/post_actions.py

@@ -6,8 +6,6 @@ import logging
 from pathlib import Path
 from typing import TYPE_CHECKING
 
-from PySide6.QtWidgets import QMessageBox
-
 from ..core.cache import download_image
 
 if TYPE_CHECKING:
@@ -163,6 +161,7 @@ class PostActionsController:
         self._app._popout_ctrl.update_state()
 
     def blacklist_tag_from_popout(self, tag: str) -> None:
+        from PySide6.QtWidgets import QMessageBox
         reply = QMessageBox.question(
             self._app, "Blacklist Tag",
             f"Blacklist tag \"{tag}\"?\nPosts with this tag will be hidden.",
@@ -178,6 +177,7 @@ class PostActionsController:
     def blacklist_post_from_popout(self) -> None:
         post, idx = self.get_preview_post()
         if post:
+            from PySide6.QtWidgets import QMessageBox
             reply = QMessageBox.question(
                 self._app, "Blacklist Post",
                 f"Blacklist post #{post.id}?\nThis post will be hidden from results.",

booru_viewer/gui/search_controller.py

@@ -6,10 +6,6 @@ import asyncio
 import logging
 from typing import TYPE_CHECKING
 
-from PySide6.QtCore import QTimer
-from PySide6.QtGui import QPixmap
-from PySide6.QtWidgets import QApplication
-
 from .search_state import SearchState
 
 if TYPE_CHECKING:
@@ -293,6 +289,7 @@ class SearchController:
         self._app._next_page_btn.setVisible(not at_end)
         thumbs = self._app._grid.set_posts(len(posts))
         self._app._grid.scroll_to_top()
+        from PySide6.QtCore import QTimer
         QTimer.singleShot(100, self.clear_loading)
 
         from ..core.config import saved_dir
@@ -410,6 +407,7 @@ class SearchController:
     def on_scroll_range_changed(self, _min: int, max_val: int) -> None:
         """Scrollbar range changed (resize/splitter) -- check if viewport needs filling."""
         if max_val == 0 and self._infinite_scroll and self._app._posts:
+            from PySide6.QtCore import QTimer
             QTimer.singleShot(100, self.check_viewport_fill)
 
     def check_viewport_fill(self) -> None:
@@ -417,6 +415,7 @@ class SearchController:
         if not self._infinite_scroll or self._loading or self._search.infinite_exhausted:
             return
         self._app._grid.widget().updateGeometry()
+        from PySide6.QtWidgets import QApplication
         QApplication.processEvents()
         sb = self._app._grid.verticalScrollBar()
         if sb.maximum() == 0 and self._app._posts:
@@ -434,6 +433,7 @@ class SearchController:
                 ss.infinite_exhausted = True
                 self._app._status.showMessage(f"{len(self._app._posts)} results (end)")
             else:
+                from PySide6.QtCore import QTimer
                 QTimer.singleShot(100, self.check_viewport_fill)
             return
         if ss.infinite_last_page > self._current_page:
@@ -501,6 +501,7 @@ class SearchController:
         self._app._run_async(_download)
 
     def on_thumb_done(self, index: int, path: str) -> None:
+        from PySide6.QtGui import QPixmap
         thumbs = self._app._grid._thumbs
         if 0 <= index < len(thumbs):
             pix = QPixmap(path)

booru_viewer/gui/window_state.py

@@ -8,8 +8,6 @@ import os
 import subprocess
 from typing import TYPE_CHECKING
 
-from PySide6.QtCore import QTimer
-
 if TYPE_CHECKING:
     from .main_window import BooruApp
 
@@ -252,6 +250,7 @@ class WindowStateController:
             return
         # Slight delay so the window is registered before we try to find
         # its address. The popout uses the same pattern.
+        from PySide6.QtCore import QTimer
         QTimer.singleShot(
             50, lambda: self.hyprctl_apply_main_state(x, y, w, h, was_floating)
         )