feat(ai-outfit): button palette matching the print module (§19.11)

Panel had no stylesheet -> all buttons rendered native gray. Add
setObjectName('aiOutfitPanel') + _apply_styles() with QSS scoped to
#aiOutfitPanel (so dialogs keep native buttons): primary blue for 开始生成
(aiStartBtn, mirrors 开始批量导出/打开文件夹), quiet red for 停止生成 and the 话术
删除 (aiStopBtn/aiPromptDeleteBtn, mirrors 删除), secondary gray for the rest.
docs/11 §10.5 + tasks §19.11. Offscreen grab verified; full suite (12) green.

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

src/app/widgets/ai_outfit_panel.py

@@ -158,6 +158,7 @@ class AiOutfitPanel(QWidget):
     # -- construction ---------------------------------------------------
 
     def _build_ui(self):
+        self.setObjectName("aiOutfitPanel")
         outer = QVBoxLayout(self)
         outer.setContentsMargins(0, 0, 0, 0)
 
@@ -171,6 +172,57 @@ class AiOutfitPanel(QWidget):
         splitter.setStretchFactor(2, 0)
         splitter.setSizes([360, 540, 400])
         outer.addWidget(splitter)
+        self._apply_styles()
+
+    def _apply_styles(self):
+        """Button palette mirroring the 添加印花 widgets (docs/11 §10.5).
+
+        Scoped under #aiOutfitPanel so QMessageBox/QInputDialog buttons keep the
+        native look. Blue = the single primary action (开始生成); red = stop/delete;
+        everything else is the neutral secondary used across the print panels.
+        """
+        self.setStyleSheet("""
+            #aiOutfitPanel QPushButton {
+                font-size: 12px;
+                padding: 4px 10px;
+                border: 1px solid #d6d6d6;
+                border-radius: 3px;
+                background: #f0f0f0;
+                color: #202020;
+            }
+            #aiOutfitPanel QPushButton:hover { background: #e0e0e0; }
+            #aiOutfitPanel QPushButton:pressed { background: #d0d0d0; }
+            #aiOutfitPanel QPushButton:disabled { color: #aaaaaa; background: #f7f7f7; }
+
+            #aiOutfitPanel QPushButton#aiStartBtn {
+                font-weight: bold;
+                color: #ffffff;
+                border: none;
+                background: #0078d4;
+            }
+            #aiOutfitPanel QPushButton#aiStartBtn:hover { background: #106ebe; }
+            #aiOutfitPanel QPushButton#aiStartBtn:pressed { background: #005a9e; }
+            #aiOutfitPanel QPushButton#aiStartBtn:disabled {
+                color: #aaaaaa; background: #f7f7f7;
+            }
+
+            #aiOutfitPanel QPushButton#aiStopBtn,
+            #aiOutfitPanel QPushButton#aiPromptDeleteBtn {
+                color: #c42b1c;
+                background: #f0f0f0;
+                border: 1px solid #d6d6d6;
+            }
+            #aiOutfitPanel QPushButton#aiStopBtn:hover,
+            #aiOutfitPanel QPushButton#aiPromptDeleteBtn:hover {
+                background: #fde7e9; border-color: #c42b1c;
+            }
+            #aiOutfitPanel QPushButton#aiStopBtn:pressed,
+            #aiOutfitPanel QPushButton#aiPromptDeleteBtn:pressed { background: #f9d4d7; }
+            #aiOutfitPanel QPushButton#aiStopBtn:disabled,
+            #aiOutfitPanel QPushButton#aiPromptDeleteBtn:disabled {
+                color: #aaaaaa; background: #f7f7f7; border-color: #d6d6d6;
+            }
+        """)
 
     def _build_left(self):
         scroll = QScrollArea()
@@ -207,6 +259,8 @@ class AiOutfitPanel(QWidget):
         for text, slot in (("新建", self._prompt_new), ("另存为", self._prompt_save_as),
                            ("重命名", self._prompt_rename), ("删除", self._prompt_delete)):
             b = QPushButton(text)
+            if text == "删除":
+                b.setObjectName("aiPromptDeleteBtn")
             b.clicked.connect(slot)
             trow.addWidget(b)
         pv.addLayout(trow)
@@ -378,10 +432,11 @@ class AiOutfitPanel(QWidget):
 
         run_row = QHBoxLayout()
         self._start_btn = QPushButton("开始生成")
-        self._start_btn.setObjectName("primaryBtn")
+        self._start_btn.setObjectName("aiStartBtn")
         self._start_btn.clicked.connect(self._start)
         run_row.addWidget(self._start_btn)
         self._stop_btn = QPushButton("停止生成")
+        self._stop_btn.setObjectName("aiStopBtn")
         self._stop_btn.setEnabled(False)
         self._stop_btn.clicked.connect(self._stop)
         run_row.addWidget(self._stop_btn)