feat(qml): task #14b 参考图录入（添加 / 粘贴 / 拖拽）

ImageGenBridge 加 2 个 Slot:
- pasteFromClipboard() → str
  从 QGuiApplication.clipboard() 拿 image，存到 tempdir/nano_banana_app/clipboard_*.png
  (与旧 _cleanup_clipboard_tempfiles 同目录，启动期统一 24h 清理)
  失败返回 ""
- normalizeFileUrls(urls list) → list
  把 QML DropArea 给的 file:/// QUrl 列表转本地路径，过滤非图扩展名
  (.png/.jpg/.jpeg/.webp/.bmp)

ImageGenTab.qml:
- import QtQuick.Dialogs 引入 FileDialog (现代 QML6 module)
- "添加图片" → addImageDialog.open() (multi-select 图片)
- " 粘贴图片" → imageGen.pasteFromClipboard()，无图时状态变橙色"剪贴板没有图片"
- 拖拽区 DropArea 接 text/uri-list，containsDrag 时边框变 accent + 底色变 accentSubtle
  drop 后调 imageGen.normalizeFileUrls(drop.urls) 拿本地路径
- 已选图缩略图 Flow:
  ScrollView + Repeater 96×96 圆角缩略图 + 右上角红色 × 删除按钮
- addRefPath/addRefPaths/removeRefAt 三个辅助函数处理状态去重和增量

未做（task #14c/d）：
- 提示词收藏 / 删除 saved_prompts 持久化
- 下载图片 + 双击预览打开系统查看器

视觉验证：QML_AUTO_LOGIN=1 启动主窗口，参考图区按钮全 enabled，UI 无回归。

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

@@ -6,9 +6,14 @@ QML 调 imageGen.submitTask(prompt, refs, aspect, size, mode) → 桥层把 mode
 然后把 result_path 通过 taskCompleted 信号转出（QML 只拿到文件路径，不传 bytes）。
 """
 import logging
+import tempfile
+import time
+import uuid
+from pathlib import Path
 from typing import Optional
 
-from PySide6.QtCore import Property, QObject, Signal, Slot
+from PySide6.QtCore import Property, QObject, QUrl, Signal, Slot
+from PySide6.QtGui import QGuiApplication
 
 from core.generation import MODEL_BY_MODE, MODEL_PRO
 
@@ -89,6 +94,47 @@ class ImageGenBridge(QObject):
         self._tqm.cancel_task(task_id)
         self.busyChanged.emit()
 
+    @Slot(result=str)
+    def pasteFromClipboard(self) -> str:
+        """从系统剪贴板拿图片，存到 temp 目录，返回本地路径。
+
+        失败（剪贴板无图）返回空字符串。tempdir 启动期已被
+        _cleanup_clipboard_tempfiles 清过 24h+ 旧文件。
+        """
+        clipboard = QGuiApplication.clipboard()
+        if clipboard is None:
+            return ""
+        image = clipboard.image()
+        if image.isNull():
+            return ""
+
+        tmp_dir = Path(tempfile.gettempdir()) / "nano_banana_app"
+        tmp_dir.mkdir(parents=True, exist_ok=True)
+        ts = time.strftime("%Y%m%d_%H%M%S")
+        path = tmp_dir / f"clipboard_{ts}_{uuid.uuid4().hex[:6]}.png"
+        if not image.save(str(path), "PNG"):
+            self._logger.warning(f"剪贴板图片保存失败: {path}")
+            return ""
+        self._logger.info(f"剪贴板图片已存: {path}")
+        return str(path)
+
+    @Slot("QVariantList", result="QVariantList")
+    def normalizeFileUrls(self, urls) -> list:
+        """QML DropArea 给的是 file:/// QUrl 列表，转成本地路径字符串列表（过滤非图片）。"""
+        result = []
+        valid_ext = {".png", ".jpg", ".jpeg", ".webp", ".bmp"}
+        for u in urls or []:
+            try:
+                if isinstance(u, QUrl):
+                    p = u.toLocalFile()
+                else:
+                    p = QUrl(str(u)).toLocalFile() or str(u)
+                if p and Path(p).suffix.lower() in valid_ext:
+                    result.append(p)
+            except Exception:
+                continue
+        return result
+
     # ---- 内部信号转发 ----------------------------------------------------
 
     def _on_task_added(self, task) -> None:

 import QtQuick
 import QtQuick.Controls.Basic
+import QtQuick.Dialogs
 import QtQuick.Layouts
 import "components"
 import "." as App
@@ -8,12 +9,36 @@ Item {
     id: tab
 
     // ===== 状态 =====
-    property var refImages: []           // list[str] 参考图本地路径，task #14b 接上传/粘贴/拖拽
+    property var refImages: []           // list[str] 参考图本地路径
     property string currentTaskId: ""    // 当前进行中的任务 id（同一时刻最多一个）
     property string lastResultPath: ""   // 最近一次 taskCompleted 的图片路径
     property string statusText: "● 就绪"
     property color statusColor: App.Theme.success
 
+    function addRefPath(p) {
+        if (!p) return
+        if (tab.refImages.indexOf(p) >= 0) return  // 去重
+        tab.refImages = tab.refImages.concat([p])
+    }
+    function addRefPaths(paths) {
+        for (var i = 0; i < (paths || []).length; i++) {
+            addRefPath(paths[i])
+        }
+    }
+    function removeRefAt(idx) {
+        var copy = tab.refImages.slice()
+        copy.splice(idx, 1)
+        tab.refImages = copy
+    }
+
+    FileDialog {
+        id: addImageDialog
+        title: "选择参考图片"
+        fileMode: FileDialog.OpenFiles
+        nameFilters: ["图片 (*.png *.jpg *.jpeg *.webp *.bmp)"]
+        onAccepted: tab.addRefPaths(imageGen.normalizeFileUrls(selectedFiles))
+    }
+
     // ===== 桥层信号 =====
     Connections {
         target: imageGen
@@ -94,8 +119,21 @@ Item {
 
                 RowLayout {
                     spacing: App.Theme.space2
-                    SecondaryButton { text: "添加图片"; enabled: false }
-                    SecondaryButton { text: "📋 粘贴图片"; enabled: false }
+                    SecondaryButton {
+                        text: "添加图片"
+                        onClicked: addImageDialog.open()
+                    }
+                    SecondaryButton {
+                        text: "📋 粘贴图片"
+                        onClicked: {
+                            var p = imageGen.pasteFromClipboard()
+                            if (p) tab.addRefPath(p)
+                            else {
+                                tab.statusText = "● 剪贴板没有图片"
+                                tab.statusColor = App.Theme.warning
+                            }
+                        }
+                    }
                     Label {
                         text: "已选择 " + tab.refImages.length + " 张"
                         font.family: App.Theme.fontFamily
@@ -112,12 +150,13 @@ Item {
                 }
 
                 Rectangle {
+                    id: dropZone
                     Layout.fillWidth: true
                     Layout.fillHeight: true
-                    color: App.Theme.bgSubtle
+                    color: dropArea.containsDrag ? App.Theme.accentSubtle : App.Theme.bgSubtle
                     radius: App.Theme.radiusMd
                     border.width: 2
-                    border.color: App.Theme.borderDefault
+                    border.color: dropArea.containsDrag ? App.Theme.accent : App.Theme.borderDefault
 
                     Text {
                         anchors.centerIn: parent
@@ -125,6 +164,76 @@ Item {
                         color: App.Theme.textTertiary
                         font.family: App.Theme.fontFamily
                         font.pointSize: App.Theme.fontSm
+                        visible: tab.refImages.length === 0
+                    }
+
+                    // 缩略图 Flow（有图时显示）
+                    ScrollView {
+                        anchors.fill: parent
+                        anchors.margins: App.Theme.space2
+                        clip: true
+                        visible: tab.refImages.length > 0
+
+                        Flow {
+                            width: dropZone.width - App.Theme.space2 * 2
+                            spacing: App.Theme.space2
+
+                            Repeater {
+                                model: tab.refImages
+                                delegate: Rectangle {
+                                    width: 96
+                                    height: 96
+                                    radius: App.Theme.radiusSm
+                                    color: App.Theme.bgSurface
+                                    border.width: 1
+                                    border.color: App.Theme.borderDefault
+
+                                    Image {
+                                        anchors.fill: parent
+                                        anchors.margins: 2
+                                        source: "file:///" + modelData
+                                        fillMode: Image.PreserveAspectCrop
+                                        smooth: true
+                                        asynchronous: true
+                                    }
+
+                                    // 右上角删除按钮
+                                    Rectangle {
+                                        width: 20; height: 20; radius: 10
+                                        color: App.Theme.danger
+                                        anchors.top: parent.top
+                                        anchors.right: parent.right
+                                        anchors.margins: 2
+
+                                        Text {
+                                            anchors.centerIn: parent
+                                            text: "×"
+                                            color: "white"
+                                            font.pixelSize: 14
+                                            font.weight: Font.Bold
+                                        }
+
+                                        MouseArea {
+                                            anchors.fill: parent
+                                            cursorShape: Qt.PointingHandCursor
+                                            onClicked: tab.removeRefAt(index)
+                                        }
+                                    }
+                                }
+                            }
+                        }
+                    }
+
+                    DropArea {
+                        id: dropArea
+                        anchors.fill: parent
+                        keys: ["text/uri-list"]
+                        onDropped: function(drop) {
+                            if (drop.urls && drop.urls.length > 0) {
+                                tab.addRefPaths(imageGen.normalizeFileUrls(drop.urls))
+                                drop.acceptProposedAction()
+                            }
+                        }
                     }
                 }
             }