fix(qt6): light mode overhaul — softer palette, theme-aware CAppBar, persist theme on startup

- Change default primary from green (#10a37f) to indigo (#6366f1/#4f46e5)
- Light theme: soft off-white (#f0f0f3) background instead of blinding #ffffff
- CAppBar now uses Theme.paper background instead of native ToolBar styling
- App.qml calls Theme.setTheme() on startup + on currentTheme change
- FrontPage uses isDark flag for all surface/border colors (works both modes)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

frontends/qt6/App.qml

@@ -335,8 +335,20 @@ ApplicationWindow {
         property alias authToken: appWindow.authToken
     }
 
+    // ── Restore persisted theme ──
+    onCurrentThemeChanged: {
+        if (typeof Theme.setTheme === "function") {
+            Theme.setTheme(currentTheme)
+        }
+    }
+
     // ── Auto-login with persisted token ──
     Component.onCompleted: {
+        // Apply saved theme on startup
+        if (typeof Theme.setTheme === "function") {
+            Theme.setTheme(currentTheme)
+        }
+
         if (authToken !== "") {
             dbalProvider.authToken = authToken
             dbalProvider.execute("core/auth/validate", { token: authToken }, function(result, error) {

frontends/qt6/FrontPage.qml

@@ -37,15 +37,17 @@ Rectangle {
 
     Component.onCompleted: loadPlatformStatus()
 
-    // ── Palette — cool/techy, no golf ──
+    // ── Palette — cool/techy, theme-aware ──
     readonly property color accentBlue: "#6366F1"    // indigo-500
     readonly property color accentCyan: "#06B6D4"    // cyan-500
     readonly property color accentViolet: "#8B5CF6"  // violet-500
     readonly property color accentAmber: "#F59E0B"   // amber-500
     readonly property color accentRose: "#F43F5E"    // rose-500
-    readonly property color subtleText: Qt.rgba(1, 1, 1, 0.45)
-    readonly property color subtleBorder: Qt.rgba(1, 1, 1, 0.08)
-    readonly property color cardBg: Qt.rgba(1, 1, 1, 0.03)
+    // Theme-aware surface colors (work in both light and dark)
+    readonly property bool isDark: Theme.mode === "dark"
+    readonly property color subtleText: isDark ? Qt.rgba(1, 1, 1, 0.45) : Qt.rgba(0, 0, 0, 0.45)
+    readonly property color subtleBorder: isDark ? Qt.rgba(1, 1, 1, 0.08) : Qt.rgba(0, 0, 0, 0.08)
+    readonly property color cardBg: isDark ? Qt.rgba(1, 1, 1, 0.03) : Qt.rgba(0, 0, 0, 0.02)
 
     // ── Level definitions ──
     property var levels: [
@@ -115,14 +117,14 @@ Rectangle {
                 Layout.preferredHeight: 360
                 color: "transparent"
 
-                // Subtle gradient — indigo → transparent → violet
+                // Subtle gradient — uses accent colors, theme-aware
                 Rectangle {
                     anchors.fill: parent
                     gradient: Gradient {
                         orientation: Gradient.Horizontal
-                        GradientStop { position: 0.0; color: Qt.rgba(0.39, 0.4, 0.95, 0.06) }
+                        GradientStop { position: 0.0; color: Qt.rgba(accentBlue.r, accentBlue.g, accentBlue.b, 0.06) }
                         GradientStop { position: 0.5; color: "transparent" }
-                        GradientStop { position: 1.0; color: Qt.rgba(0.55, 0.36, 0.96, 0.04) }
+                        GradientStop { position: 1.0; color: Qt.rgba(accentViolet.r, accentViolet.g, accentViolet.b, 0.04) }
                     }
                 }
 
@@ -597,7 +599,7 @@ Rectangle {
                             Layout.fillWidth: true
                             Layout.preferredHeight: 56
                             radius: 6
-                            color: credMA2.containsMouse ? Qt.rgba(0.39, 0.4, 0.95, 0.06) : cardBg
+                            color: credMA2.containsMouse ? Qt.rgba(accentBlue.r, accentBlue.g, accentBlue.b, 0.06) : cardBg
                             border.color: credMA2.containsMouse ? modelData.accent : subtleBorder
                             border.width: 1
 

qml/components/surfaces/CAppBar.qml

@@ -1,8 +1,25 @@
 import QtQuick
 import QtQuick.Controls
 import QtQuick.Layouts
+import QmlComponents 1.0
 
 ToolBar {
     id: appbar
+
+    background: Rectangle {
+        color: Theme.paper
+        border.color: Theme.border
+        border.width: 1
+
+        // Bottom border only
+        Rectangle {
+            anchors.bottom: parent.bottom
+            anchors.left: parent.left
+            anchors.right: parent.right
+            height: 1
+            color: Theme.border
+        }
+    }
+
     RowLayout { anchors.fill: parent }
 }

qml/components/theming/Theme.qml

@@ -30,9 +30,9 @@ QtObject {
     
     // Theme definitions - matches React themes.js
     readonly property var themes: ({
-        system: { name: "System", mode: "dark", primary: "#10a37f", background: "#0d0d0d", paper: "#1a1a1a", surface: "#242424", text: "#ffffff", textSecondary: "#a0a0a0", border: "#333333", error: "#ef4444", warning: "#f59e0b", success: "#22c55e", info: "#3b82f6" },
-        dark: { name: "Dark", mode: "dark", primary: "#10a37f", background: "#0d0d0d", paper: "#1a1a1a", surface: "#242424", text: "#ffffff", textSecondary: "#a0a0a0", border: "#333333", error: "#ef4444", warning: "#f59e0b", success: "#22c55e", info: "#3b82f6" },
-        light: { name: "Light", mode: "light", primary: "#10a37f", background: "#ffffff", paper: "#f7f7f8", surface: "#eeeeee", text: "#1a1a1a", textSecondary: "#6e6e80", border: "#e0e0e0", error: "#d32f2f", warning: "#ed6c02", success: "#2e7d32", info: "#0288d1" },
+        system: { name: "System", mode: "dark", primary: "#6366f1", background: "#0d0d0d", paper: "#1a1a1a", surface: "#242424", text: "#ffffff", textSecondary: "#a0a0a0", border: "#333333", error: "#ef4444", warning: "#f59e0b", success: "#22c55e", info: "#3b82f6" },
+        dark: { name: "Dark", mode: "dark", primary: "#6366f1", background: "#0d0d0d", paper: "#1a1a1a", surface: "#242424", text: "#ffffff", textSecondary: "#a0a0a0", border: "#333333", error: "#ef4444", warning: "#f59e0b", success: "#22c55e", info: "#3b82f6" },
+        light: { name: "Light", mode: "light", primary: "#4f46e5", background: "#f0f0f3", paper: "#e8e8ec", surface: "#dddde2", text: "#1a1a2e", textSecondary: "#5a5a72", border: "#c8c8d4", error: "#d32f2f", warning: "#ed6c02", success: "#2e7d32", info: "#0288d1" },
         midnight: { name: "Midnight", mode: "dark", primary: "#6366f1", background: "#0f172a", paper: "#1e293b", surface: "#334155", text: "#f1f5f9", textSecondary: "#94a3b8", border: "#334155", error: "#ef4444", warning: "#f59e0b", success: "#22c55e", info: "#3b82f6" },
         forest: { name: "Forest", mode: "dark", primary: "#22c55e", background: "#0a1f0a", paper: "#14331a", surface: "#1a4d23", text: "#ecfdf5", textSecondary: "#a7f3d0", border: "#166534", error: "#ef4444", warning: "#f59e0b", success: "#22c55e", info: "#3b82f6" },
         ocean: { name: "Ocean", mode: "dark", primary: "#0ea5e9", background: "#0c1929", paper: "#132f4c", surface: "#1e4976", text: "#e0f2fe", textSecondary: "#7dd3fc", border: "#0369a1", error: "#ef4444", warning: "#f59e0b", success: "#22c55e", info: "#0ea5e9" },