feat(ai-outfit): info popup when user switches resolution/model (§19.7)

Connect QComboBox.activated (user-only) on the 分辨率 and AI 模型 dropdowns to
an info-only QMessageBox: resolution shows the per-resolution timeout +
next-run-only; model shows its api_type + billing/effect caveat + next-run-only.
Track last value so re-selecting the same item doesn't pop; programmatic sets
(apply_config/_fill_sample_combo) never pop. Offscreen-verified; suite (12) green.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/app/widgets/ai_outfit_panel.py

@@ -146,6 +146,8 @@ class AiOutfitPanel(QWidget):
         self._worker = None
         self._row_to_table = {}    # excel row_index -> table row
         self._failures = []        # list of OutfitResult (failed)
+        self._last_resolution = ""  # for "value actually changed" check (§10.2)
+        self._last_model = ""
         self._build_ui()
 
     # -- construction ---------------------------------------------------
@@ -246,6 +248,8 @@ class AiOutfitPanel(QWidget):
         self._resolution = QComboBox()
         self._resolution.addItems(_RESOLUTIONS)
         self._resolution.currentIndexChanged.connect(self._refresh_preview)
+        # activated = user click only; programmatic sets won't pop (docs/11 §10.2)
+        self._resolution.activated.connect(self._on_resolution_activated)
         self._quality = QComboBox()
         self._quality.addItems(_QUALITIES)
 
@@ -266,6 +270,7 @@ class AiOutfitPanel(QWidget):
         # AI 模型 下拉（移到生成设置下方）
         self._model_combo = QComboBox()
         self._compact_combo(self._model_combo)
+        self._model_combo.activated.connect(self._on_model_activated)
         gv.addWidget(self._field("AI 模型", self._model_combo))
         return gen
 
@@ -395,6 +400,11 @@ class AiOutfitPanel(QWidget):
                 self._model_combo.addItem(m.get("name") or m.get("model") or "(未命名)")
             self._set_combo(self._model_combo, config.get("outfit_model", ""))
 
+        # Snapshot current dropdown values so a later user re-select of the same
+        # item doesn't trigger the info popup (§10.2).
+        self._last_resolution = self._resolution.currentText()
+        self._last_model = self._model_combo.currentText() if self._models else ""
+
         # Fill the preview's sample-row dropdown from the remembered Excel.
         self._reload_sample_rows()
 
@@ -483,6 +493,37 @@ class AiOutfitPanel(QWidget):
         else:
             self._preview_view.setPlainText(render_prompt(template, task, resolution))
 
+    # -- switch info popups (user-only; §10.2) --------------------------
+
+    def _on_resolution_activated(self, _index):
+        res = self._resolution.currentText()
+        if res == self._last_resolution:
+            return
+        self._last_resolution = res
+        from services.ai_image_service import resolution_timeout
+        QMessageBox.information(
+            self, "分辨率已切换",
+            "已切换分辨率到 {}。\n\n"
+            "· 单任务超时约 {} 秒，分辨率越高越慢。\n"
+            "· 仅在下次「开始生成」生效，不影响正在进行的批次。".format(
+                res, resolution_timeout(res)))
+
+    def _on_model_activated(self, _index):
+        name = self._model_combo.currentText()
+        if name == self._last_model:
+            return
+        self._last_model = name
+        api_type = "auto"
+        idx = self._model_combo.currentIndex()
+        if self._models and 0 <= idx < len(self._models):
+            api_type = self._models[idx].get("api_type", "auto") or "auto"
+        QMessageBox.information(
+            self, "AI 模型已切换",
+            "已切换模型到 {}。\n\n"
+            "· 调用方式：{}。\n"
+            "· 不同模型的计费与效果可能不同。\n"
+            "· 仅在下次「开始生成」生效。".format(name, api_type))
+
     # -- run control ----------------------------------------------------
 
     def _start(self):