[PictureLoader] Fix custom-folder pictures in subdirectories not loading (#7340)

CardPictureLoaderLocal compared the full file name (including extension)
of the custom-folder candidate against the extension-stripped base name of
each directory entry, so a CUSTOM subfolder image like
pics/CUSTOM/poker/1 of Hearts.png never matched and the card fell through
to the network. Compare the complete base names instead.

Add matcher tests covering CUSTOM subfolder resolution.

Co-authored-by: Lukas Brübach <Bruebach.Lukas@bdosecurity.de>

tests/loader_local_matching_test.cpp

@@ -68,6 +68,18 @@ protected:
         loader = nullptr;
     }
 
+    /**
+     * @brief Destroys and rebuilds the loader so the CUSTOM index is re-scanned.
+     *
+     * The CUSTOM-folder index is snapshotted at construction; rebuild it after
+     * writing files so freshly placed images are discoverable.
+     */
+    void rebuildLoader()
+    {
+        delete loader;
+        loader = new CardPictureLoaderLocal(nullptr);
+    }
+
     /**
      * @brief Writes a valid 1x1 PNG under the sandboxed pics path.
      */
@@ -162,6 +174,28 @@ TEST_F(LocalMatcherTest, SetFolderCandidateTakesPrecedenceOverRootFallback)
     EXPECT_EQ(image.pixelColor(0, 0), QColor(Qt::red)) << "The set-folder candidate must be preferred";
 }
 
+TEST_F(LocalMatcherTest, CustomSubfolderResolvesExactFile)
+{
+    // Images in the CUSTOM folder are indexed by their full file path (extension included),
+    // unlike the extension-less candidate paths built from the naming schemes.
+    writePngUnderPics("CUSTOM/poker/TestCard.png");
+    rebuildLoader();
+
+    const QImage image = loader->tryLoad(cardFor("TestCard", "", ""));
+
+    EXPECT_FALSE(image.isNull()) << "A CUSTOM-folder image in a subdirectory must resolve";
+}
+
+TEST_F(LocalMatcherTest, CustomSubfolderIgnoresSuffixedFiles)
+{
+    writePngUnderPics("CUSTOM/poker/TestCard (1).png");
+    rebuildLoader();
+
+    const QImage image = loader->tryLoad(cardFor("TestCard", "", ""));
+
+    EXPECT_TRUE(image.isNull()) << "A suffixed CUSTOM-folder file must not satisfy an exact name lookup";
+}
+
 } // namespace
 
 int main(int argc, char **argv)