fix: Improve Plugin Store layout - larger cards and proper sizing

Changes:
- Plugin cards now 320x220 minimum (was 300x200 fixed)
- Cards have maximum width of 400px to prevent stretching too wide
- PluginStoreUI now fills available space with stretch factor
- Grid layout calculates columns based on available width
- Removed hardcoded margins that were causing cramped layout
- Search input now has minimum width of 300px
- Buttons have minimum widths for consistent sizing

core/perfect_ux.py

@@ -1143,7 +1143,7 @@ class PerfectMainWindow(QMainWindow):
             from core.plugin_store import PluginStoreUI
             if self.plugin_manager:
                 store_ui = PluginStoreUI(self.plugin_manager)
-                store_layout.addWidget(store_ui)
+                store_layout.addWidget(store_ui, 1)  # Add stretch factor to fill space
             else:
                 raise Exception("PluginManager not available")
         except Exception as e:
@@ -1154,9 +1154,9 @@ class PerfectMainWindow(QMainWindow):
             ph_text.setAlignment(Qt.AlignmentFlag.AlignCenter)
             ph_layout.addWidget(ph_text)
             placeholder.set_content(ph_layout)
-            store_layout.addWidget(placeholder)
+            store_layout.addWidget(placeholder, 1)  # Add stretch factor
         
-        store_layout.addStretch()
+        # Remove the addStretch() - the widget should fill the space
         tabs.addTab(store_tab, "Store")
         
         layout.addWidget(tabs)

core/plugin_store.py

@@ -197,7 +197,7 @@ class PluginStoreUI(QWidget):
         """Create the UI."""
         layout = QVBoxLayout(self)
         layout.setSpacing(15)
-        layout.setContentsMargins(20, 20, 20, 20)
+        layout.setContentsMargins(0, 0, 0, 0)  # Remove margins to fill parent
         
         # Header
         header = QLabel("🔌 Plugin Store")
@@ -232,6 +232,7 @@ class PluginStoreUI(QWidget):
         
         self.search_input = QLineEdit()
         self.search_input.setPlaceholderText("🔍 Search plugins...")
+        self.search_input.setMinimumWidth(300)
         self.search_input.setStyleSheet("""
             QLineEdit {
                 background-color: rgba(30, 35, 45, 200);
@@ -246,6 +247,7 @@ class PluginStoreUI(QWidget):
         
         self.category_combo = QComboBox()
         self.category_combo.addItem("All Categories")
+        self.category_combo.setMinimumWidth(150)
         self.category_combo.setStyleSheet("""
             QComboBox {
                 background-color: rgba(30, 35, 45, 200);
@@ -267,6 +269,7 @@ class PluginStoreUI(QWidget):
         filter_layout.addWidget(self.category_combo, 1)
         
         self.refresh_btn = QPushButton("🔄 Refresh")
+        self.refresh_btn.setMinimumWidth(100)
         self.refresh_btn.setStyleSheet("""
             QPushButton {
                 background-color: #4a9eff;
@@ -284,6 +287,7 @@ class PluginStoreUI(QWidget):
         filter_layout.addWidget(self.refresh_btn)
         
         self.check_updates_btn = QPushButton("📥 Check Updates")
+        self.check_updates_btn.setMinimumWidth(120)
         self.check_updates_btn.setStyleSheet("""
             QPushButton {
                 background-color: #ff8c42;
@@ -302,19 +306,21 @@ class PluginStoreUI(QWidget):
         
         layout.addLayout(filter_layout)
         
-        # Plugin grid
+        # Plugin grid - make it expand to fill space
         self.scroll = QScrollArea()
         self.scroll.setWidgetResizable(True)
         self.scroll.setFrameShape(QFrame.Shape.NoFrame)
         self.scroll.setStyleSheet("background: transparent; border: none;")
+        self.scroll.setHorizontalScrollBarPolicy(Qt.ScrollBarPolicy.ScrollBarAlwaysOff)
         
         self.grid_widget = QWidget()
         self.grid_layout = QGridLayout(self.grid_widget)
-        self.grid_layout.setSpacing(15)
+        self.grid_layout.setSpacing(20)
+        self.grid_layout.setContentsMargins(10, 10, 10, 10)
         self.grid_layout.setAlignment(Qt.AlignmentFlag.AlignTop | Qt.AlignmentFlag.AlignLeft)
         
         self.scroll.setWidget(self.grid_widget)
-        layout.addWidget(self.scroll)
+        layout.addWidget(self.scroll, 1)  # Add stretch factor to fill space
     
     def _load_plugins(self):
         """Load available plugins from repository."""
@@ -388,18 +394,25 @@ class PluginStoreUI(QWidget):
             self.grid_layout.addWidget(no_results, 0, 0)
             return
         
-        # Create cards
-        columns = 3
+        # Create cards - use minimum 2 columns, expand to fill
+        # Calculate columns based on available width
+        available_width = self.scroll.width() - 40  # Account for margins
+        card_width = 340  # Card width + spacing
+        columns = max(2, available_width // card_width)
+        
         for i, plugin in enumerate(self.filtered_plugins):
             card = self._create_plugin_card(plugin)
             row = i // columns
             col = i % columns
             self.grid_layout.addWidget(card, row, col)
+            # Make columns stretch evenly
+            self.grid_layout.setColumnStretch(col, 1)
     
     def _create_plugin_card(self, plugin: PluginInfo) -> QFrame:
         """Create a plugin card widget."""
         card = QFrame()
-        card.setFixedSize(300, 200)
+        card.setMinimumSize(320, 220)
+        card.setMaximumWidth(400)
         card.setStyleSheet("""
             QFrame {
                 background-color: rgba(35, 40, 55, 200);