refactor: archive GUI clients; keep minimal TUI with hooks/API

Move Qt/Tauri/full Web SPA under archive/, ship hermit as CLI/TUI plus
libcstcore and cst-webui/1 HTTP+SSE (turn lifecycle hooks, capabilities).

Co-authored-by: Cursor <cursoragent@cursor.com>

archive/qt-app/qml/ThemeIcon.qml

@@ -0,0 +1,50 @@
+import QtQuick
+
+// One icon, from the desktop's icon theme (image://csttheme/, see
+// app/src/ui/ThemeIcons.cpp), tinted with a color of the window's own.
+//
+// `glyph` is the last resort: a machine with no icon theme at all gets the
+// unicode character the app used before, rather than an empty hole. Every
+// place that shows an icon names its glyph, so nothing can go blank.
+Item {
+    id: root
+    property string name: ""
+    property string glyph: ""
+    property color color: Theme.textDim
+    property int size: 16
+    implicitWidth: size
+    implicitHeight: size
+
+    /* "#rrggbb": a color typed to a string in QML carries alpha and a
+     * leading '#', which the provider's query would choke on. */
+    function hex(c) {
+        function two(v) {
+            const s = Math.round(Math.max(0, Math.min(1, v)) * 255).toString(16)
+            return s.length < 2 ? "0" + s : s
+        }
+        return "#" + two(c.r) + two(c.g) + two(c.b)
+    }
+
+    Image {
+        id: img
+        anchors.fill: parent
+        source: root.name.length
+                ? "image://csttheme/" + root.name + "?color=" + encodeURIComponent(root.hex(root.color))
+                : ""
+        sourceSize.width: root.size
+        sourceSize.height: root.size
+        fillMode: Image.PreserveAspectFit
+        smooth: true
+        visible: status === Image.Ready
+    }
+
+    Text {
+        anchors.fill: parent
+        visible: img.status === Image.Error && root.glyph.length > 0
+        text: root.glyph
+        color: root.color
+        font.pixelSize: Math.round(root.size * 0.85)
+        horizontalAlignment: Text.AlignHCenter
+        verticalAlignment: Text.AlignVCenter
+    }
+}