fix(touch): improve text visibility in dark mode

- Fix placeholderText color in ThemeManager (#606060 -> #9a9a9a)
  The old color was nearly invisible on dark backgrounds
- Add placeholderTextColor to all search TextField components
- Add proper text colors to PatternListPage search field
- Add Components import alias to PatternListPage for ThemeManager access

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

dune-weaver-touch/qml/components/ThemeManager.qml

@@ -42,7 +42,7 @@ QtObject {
 
     // Placeholder colors
     property color placeholderBackground: darkMode ? "#2d2d2d" : "#f0f0f0"
-    property color placeholderText: darkMode ? "#606060" : "#cccccc"
+    property color placeholderText: darkMode ? "#9a9a9a" : "#999999"
 
     // Preview background - lighter in dark mode for better pattern visibility
     property color previewBackground: darkMode ? "#707070" : "#f8f9fa"

dune-weaver-touch/qml/pages/ModernPatternListPage.qml

@@ -158,6 +158,7 @@ Page {
                             id: searchField
                             Layout.fillWidth: true
                             placeholderText: searchExpanded ? "Search patterns... (press Enter)" : "Search"
+                            placeholderTextColor: Components.ThemeManager.textTertiary
                             font.pixelSize: 14
                             color: Components.ThemeManager.textPrimary
                             visible: searchExpanded || text.length > 0

dune-weaver-touch/qml/pages/PatternListPage.qml

@@ -2,6 +2,7 @@ import QtQuick 2.15
 import QtQuick.Controls 2.15
 import QtQuick.Layouts 1.15
 import "../components"
+import "../components" as Components
 
 Page {
     id: page
@@ -15,6 +16,8 @@ Page {
                 id: searchField
                 Layout.fillWidth: true
                 placeholderText: "Search patterns..."
+                placeholderTextColor: Components.ThemeManager.textTertiary
+                color: Components.ThemeManager.textPrimary
                 onTextChanged: patternModel.filter(text)
                 font.pixelSize: 16
             }

dune-weaver-touch/qml/pages/PatternSelectorPage.qml

@@ -147,6 +147,7 @@ Page {
                             id: searchField
                             Layout.fillWidth: true
                             placeholderText: searchExpanded ? "Search patterns... (press Enter)" : "Search"
+                            placeholderTextColor: Components.ThemeManager.textTertiary
                             font.pixelSize: 14
                             color: Components.ThemeManager.textPrimary
                             visible: searchExpanded || text.length > 0