feat(loadout): add plate search button to each armor slot

- Each armor slot now has a 🔍 button for plate selection
- Opens PlateSelectorDialog filtered by armor's highest protection type
- Selected plates from API are added to the slot's combo box
- Plates auto-selected after API selection

ui/loadout_manager.py

@@ -25,7 +25,7 @@ from PyQt6.QtCore import Qt, pyqtSignal, QThread
 from PyQt6.QtGui import QFont
 
 from core.nexus_api import EntropiaNexusAPI, WeaponStats, ArmorStats, FinderStats
-from core.nexus_full_api import get_nexus_api, NexusArmor, NexusHealingTool
+from core.nexus_full_api import get_nexus_api, NexusArmor, NexusHealingTool, NexusPlate
 from core.attachments import (
     Attachment, WeaponAmplifier, WeaponScope, WeaponAbsorber,
     ArmorPlating, Enhancer, can_attach, get_mock_attachments
@@ -409,6 +409,13 @@ class ArmorSlotWidget(QWidget):
         self.plate_combo.currentTextChanged.connect(self._on_plate_changed)
         layout.addWidget(self.plate_combo)
         
+        # Add plate search button
+        self.search_plate_btn = QPushButton("🔍")
+        self.search_plate_btn.setToolTip("Search plates from Nexus API")
+        self.search_plate_btn.setFixedWidth(40)
+        self.search_plate_btn.clicked.connect(self._on_search_plate)
+        layout.addWidget(self.search_plate_btn)
+        
         # Total protection
         self.total_label = QLabel("Total: 0")
         self.total_label.setStyleSheet("color: #4caf50; font-weight: bold;")
@@ -455,6 +462,48 @@ class ArmorSlotWidget(QWidget):
             display = f"{plate.name} (+{plate.get_total_protection()})"
             self.plate_combo.addItem(display, plate)
     
+    def _on_search_plate(self):
+        """Open plate selector dialog from Nexus API."""
+        from ui.plate_selector import PlateSelectorDialog
+        
+        # Get current piece's protection to suggest matching plates
+        preferred_type = ""
+        if self.current_piece:
+            # Find highest protection type
+            protections = {
+                'impact': self.current_piece.protection.impact,
+                'cut': self.current_piece.protection.cut,
+                'stab': self.current_piece.protection.stab,
+                'burn': self.current_piece.protection.burn,
+                'cold': self.current_piece.protection.cold,
+            }
+            preferred_type = max(protections, key=protections.get)
+        
+        dialog = PlateSelectorDialog(self, damage_type=preferred_type)
+        dialog.plate_selected.connect(self._on_api_plate_selected)
+        dialog.exec()
+    
+    def _on_api_plate_selected(self, plate: NexusPlate):
+        """Handle plate selection from API."""
+        # Add to combo if not exists
+        index = self.plate_combo.findText(plate.name)
+        if index < 0:
+            # Create ArmorPlate from NexusPlate
+            from core.armor_system import ArmorPlate as LocalArmorPlate
+            local_plate = LocalArmorPlate(
+                name=plate.name,
+                item_id=plate.item_id,
+                protection=plate.protection,
+                durability=plate.durability,
+                decay_per_hp=plate.decay_per_hp
+            )
+            display = f"{plate.name} (+{plate.protection_impact + plate.protection_cut + plate.protection_stab} prot)"
+            self.plate_combo.addItem(display, local_plate)
+            index = self.plate_combo.count() - 1
+        
+        self.plate_combo.setCurrentIndex(index)
+        self._update_total()
+    
     def _on_piece_changed(self, text: str):
         """Handle armor piece selection."""
         if text == "-- Empty --":