feat(attachments): add attachment system and DPP display

- Created core/attachments.py with full attachment type system
- Supports: Amplifiers, Scopes, Absorbers, Finder Amps, Platings, Enhancers, Implants
- Added DPP display to HUD overlay
- Attachment compatibility validation rules

core/attachments.py

@@ -0,0 +1,196 @@
+"""
+Attachment System for Lemontropia Suite
+Defines all attachment types and their compatibility with gear.
+"""
+
+from dataclasses import dataclass
+from decimal import Decimal
+from typing import Optional, List
+
+
+@dataclass
+class Attachment:
+    """Base class for all attachments."""
+    name: str
+    item_id: str
+    decay_pec: Decimal
+    attachment_type: str  # e.g., 'amplifier', 'scope', 'absorber'
+    
+    # Effects
+    damage_bonus: Decimal = Decimal('0')
+    range_bonus: Decimal = Decimal('0')
+    efficiency_bonus: Decimal = Decimal('0')
+    
+    def calculate_cost_per_use(self) -> Decimal:
+        """Calculate cost per use in PED."""
+        return self.decay_pec / Decimal('100')
+
+
+@dataclass  
+class WeaponAmplifier(Attachment):
+    """Weapon amplifier attachment."""
+    damage_increase: Decimal = Decimal('0')
+    ammo_increase: int = 0
+    
+    def __post_init__(self):
+        self.attachment_type = 'amplifier'
+
+
+@dataclass
+class WeaponScope(Attachment):
+    """Weapon scope attachment."""
+    range_increase: Decimal = Decimal('0')
+    accuracy_bonus: Decimal = Decimal('0')
+    
+    def __post_init__(self):
+        self.attachment_type = 'scope'
+
+
+@dataclass
+class WeaponAbsorber(Attachment):
+    """Weapon absorber (reduces damage taken)."""
+    damage_reduction: Decimal = Decimal('0')
+    
+    def __post_init__(self):
+        self.attachment_type = 'absorber'
+
+
+@dataclass
+class FinderAmplifier(Attachment):
+    """Mining finder amplifier."""
+    depth_increase: Decimal = Decimal('0')
+    radius_increase: Decimal = Decimal('0')
+    
+    def __post_init__(self):
+        self.attachment_type = 'finder_amp'
+
+
+@dataclass
+class ArmorPlating(Attachment):
+    """Armor plating for increased protection."""
+    protection_stab: Decimal = Decimal('0')
+    protection_cut: Decimal = Decimal('0')
+    protection_impact: Decimal = Decimal('0')
+    protection_penetration: Decimal = Decimal('0')
+    protection_shrapnel: Decimal = Decimal('0')
+    protection_burn: Decimal = Decimal('0')
+    protection_cold: Decimal = Decimal('0')
+    protection_acid: Decimal = Decimal('0')
+    protection_electric: Decimal = Decimal('0')
+    
+    def __post_init__(self):
+        self.attachment_type = 'plating'
+    
+    def get_total_protection(self) -> Decimal:
+        """Get total protection value."""
+        return (
+            self.protection_stab + self.protection_cut + self.protection_impact +
+            self.protection_penetration + self.protection_shrapnel +
+            self.protection_burn + self.protection_cold + 
+            self.protection_acid + self.protection_electric
+        )
+
+
+@dataclass
+class Enhancer(Attachment):
+    """Gear enhancer (adds special effects)."""
+    tier: int = 1
+    effect_name: str = ""
+    effect_value: Decimal = Decimal('0')
+    
+    def __post_init__(self):
+        self.attachment_type = 'enhancer'
+
+
+@dataclass
+class MindforceImplant(Attachment):
+    """Mindforce implant for mindforce chips."""
+    mindforce_bonus: Decimal = Decimal('0')
+    
+    def __post_init__(self):
+        self.attachment_type = 'implant'
+
+
+# ============================================================================
+# Attachment Compatibility Rules
+# ============================================================================
+
+ATTACHMENT_COMPATIBILITY = {
+    'weapon': ['amplifier', 'scope', 'absorber', 'enhancer'],
+    'armor': ['plating', 'enhancer'],
+    'finder': ['finder_amp', 'enhancer'],
+    'mindforce': ['implant', 'enhancer'],
+    'tool': ['enhancer'],
+}
+
+
+def can_attach(gear_type: str, attachment_type: str) -> bool:
+    """Check if attachment is compatible with gear type."""
+    compatible = ATTACHMENT_COMPATIBILITY.get(gear_type, [])
+    return attachment_type in compatible
+
+
+def get_compatible_attachments(gear_type: str) -> List[str]:
+    """Get list of compatible attachment types for gear."""
+    return ATTACHMENT_COMPATIBILITY.get(gear_type, [])
+
+
+# ============================================================================
+# Mock Attachment Data (until API is available)
+# ============================================================================
+
+MOCK_AMPLIFIERS = [
+    WeaponAmplifier("A101", "amp_a101", Decimal("0.05"), damage_increase=Decimal("4"), ammo_increase=10),
+    WeaponAmplifier("A102", "amp_a102", Decimal("0.08"), damage_increase=Decimal("6"), ammo_increase=15),
+    WeaponAmplifier("A103", "amp_a103", Decimal("0.12"), damage_increase=Decimal("8"), ammo_increase=20),
+    WeaponAmplifier("A104", "amp_a104", Decimal("0.18"), damage_increase=Decimal("12"), ammo_increase=30),
+    WeaponAmplifier("A105", "amp_a105", Decimal("0.25"), damage_increase=Decimal("16"), ammo_increase=40),
+    WeaponAmplifier("A106", "amp_a106", Decimal("0.35"), damage_increase=Decimal("20"), ammo_increase=50),
+]
+
+MOCK_SCOPES = [
+    WeaponScope("Longreach 4", "scope_lr4", Decimal("0.02"), range_increase=Decimal("10")),
+    WeaponScope("Longreach 6", "scope_lr6", Decimal("0.04"), range_increase=Decimal("15")),
+    WeaponScope("Longreach 8", "scope_lr8", Decimal("0.06"), range_increase=Decimal("20")),
+]
+
+MOCK_ABSORBERS = [
+    WeaponAbsorber("Damage II", "abs_dmg2", Decimal("0.03"), damage_reduction=Decimal("2")),
+    WeaponAbsorber("Damage IV", "abs_dmg4", Decimal("0.05"), damage_reduction=Decimal("4")),
+]
+
+MOCK_FINDER_AMPS = [
+    FinderAmplifier("DSEC L-10", "fa_dsec10", Decimal("0.10"), depth_increase=Decimal("50"), radius_increase=Decimal("5")),
+    FinderAmplifier("DSEC L-30", "fa_dsec30", Decimal("0.25"), depth_increase=Decimal("100"), radius_increase=Decimal("10")),
+]
+
+MOCK_PLATINGS = [
+    ArmorPlating("Impact Plating", "plt_impact", Decimal("0.03"), protection_impact=Decimal("3")),
+    ArmorPlating("Cut Plating", "plt_cut", Decimal("0.03"), protection_cut=Decimal("3")),
+    ArmorPlating("Burn Plating", "plt_burn", Decimal("0.03"), protection_burn=Decimal("3")),
+]
+
+MOCK_ENHANCERS = [
+    Enhancer("Damage Enhancer 1", "enh_dmg1", Decimal("0.10"), tier=1, effect_name="damage", effect_value=Decimal("2")),
+    Enhancer("Damage Enhancer 2", "enh_dmg2", Decimal("0.15"), tier=2, effect_name="damage", effect_value=Decimal("4")),
+    Enhancer("Economy Enhancer 1", "enh_eco1", Decimal("0.08"), tier=1, effect_name="economy", effect_value=Decimal("5")),
+]
+
+MOCK_IMPLANTS = [
+    MindforceImplant("NeoPsion 10", "impl_np10", Decimal("0.05"), mindforce_bonus=Decimal("10")),
+    MindforceImplant("NeoPsion 20", "impl_np20", Decimal("0.10"), mindforce_bonus=Decimal("20")),
+]
+
+
+def get_mock_attachments(attachment_type: str) -> List[Attachment]:
+    """Get mock attachments by type."""
+    mock_data = {
+        'amplifier': MOCK_AMPLIFIERS,
+        'scope': MOCK_SCOPES,
+        'absorber': MOCK_ABSORBERS,
+        'finder_amp': MOCK_FINDER_AMPS,
+        'plating': MOCK_PLATINGS,
+        'enhancer': MOCK_ENHANCERS,
+        'implant': MOCK_IMPLANTS,
+    }
+    return mock_data.get(attachment_type, [])

ui/hud_overlay.py

@@ -422,6 +422,11 @@ class HUDOverlay(QWidget):
         self.weapon_label.setStyleSheet("font-size: 11px; color: #CCCCCC;")
         weapon_layout.addWidget(self.weapon_label)
         
+        # DPP display
+        self.dpp_label = QLabel("DPP: --")
+        self.dpp_label.setStyleSheet("font-size: 10px; color: #FFD700;")
+        weapon_layout.addWidget(self.dpp_label)
+        
         weapon_layout.addStretch()
         
         loadout_label = QLabel("Loadout:")
@@ -943,9 +948,13 @@ class HUDOverlay(QWidget):
         self.dealt_value_label.setText(str(self._stats.damage_dealt))
         self.taken_value_label.setText(str(self._stats.damage_taken))
         
-        # Weapon/Loadout
+        # Weapon/Loadout/DPP
-        self.weapon_label.setText(self._stats.current_weapon[:20])  # Truncate long names
+        self.weapon_label.setText(self._stats.current_weapon[:20])
         self.loadout_label.setText(self._stats.current_loadout[:15])
+        if self._stats.weapon_dpp > 0:
+            self.dpp_label.setText(f"DPP: {self._stats.weapon_dpp:.2f}")
+        else:
+            self.dpp_label.setText("DPP: --")
         
         # Update time if session active
         self._update_time_display()