fix(qt): the log viewer search and the Move-to-folder search open empty

Two more fields kept text across openings. The log viewer's search box and
the filter it drives both outlived a close, so the modal reopened already
filtered; opening it now clears both. The playlist manager's Move to
folder menu reset its query but not the box, which QbzLineEdit re-seeds
only while unfocused; it now resets the box too.

The remaining text fields in modals, popups and menus were checked and
already reset on open (genre filter, playlist picker, disc metadata,
replacement search, DAC wizard, sidebar row menu) or are read-only.

cc

crates/qbz-qt/qml/shell/LogViewerModal.qml

@@ -66,6 +66,12 @@ Item {
     onVisibleChanged: {
         if (visible) {
             root.advancedOpen = false
+            // A modal's fields open clean (2026-09-14): the search box and the
+            // filter it drives both outlived the close.
+            if (searchInput.text !== "") {
+                searchInput.text = ""
+                QbzShell.logSetSearch("")
+            }
             keyScope.forceActiveFocus()
         }
     }

crates/qbz-qt/qml/views/playlistmanager/PmFolderMenu.qml

@@ -83,6 +83,8 @@ QbzContextMenu {
         menuRoot.playlistId = String(pid || "")
         menuRoot.currentFolderId = String(fid || "")
         menuRoot.folderQuery = ""
+        // The box too: QbzLineEdit re-seeds only while unfocused.
+        folderSearchField.reset("")
         menuRoot.openBelowRight(anchorItem)
     }
 
@@ -103,6 +105,7 @@ QbzContextMenu {
         height: visible ? (menuRoot.kioskHost ? 44 : 32) : 0
 
         QbzLineEdit {
+            id: folderSearchField
             kioskHost: menuRoot.kioskHost
             anchors.verticalCenter: parent.verticalCenter
             // The plain arm is a FIXED width: 240 — a modal/menu must set it.