Implement Obsolete quirk effects for campaign play

  Adds campaign effects for the Obsolete quirk per BMM pg 86:
  - Maintenance rolls: +1 to +5 TN modifier based on years obsolete
  - Repair rolls: +1 to +5 TN modifier based on years obsolete
  - Resale value: 50%-100% multiplier based on years obsolete

  Changes:
  - Maintenance.java: Added obsolete modifier to getTargetForMaintenance()
  - Part.java: Added obsolete modifier to getAllMods() and
    getAllModsForMaintenance()
  - Unit.java: Applied obsolete resale modifier in getSellValue()
  - Added i18n keys for modifier descriptions

  ---
  PR Notes

  ## Summary
  Implements campaign effects for the Obsolete quirk from BattleMech Manual pg 86.

  Units with the Obsolete quirk now suffer penalties in MekHQ campaigns:
  - **Maintenance rolls**: +1 TN per 15 years obsolete (max +5)
  - **Repair rolls**: +1 TN per 15 years obsolete (max +5)
  - **Resale value**: -10% per 20 years obsolete (min 50%)

  ## Changes

  ### Maintenance & Repair TN Modifiers
  - **Maintenance.java**: Added obsolete modifier to `getTargetForMaintenance()`
  - **Part.java**: Added obsolete modifier to `getAllMods()` (repair work) and `getAllModsForMaintenance()`

  ### Resale Value
  - **Unit.java**: Applied `entity.getObsoleteResaleModifier()` in `getSellValue()` for both standard units and
  Infantry

  ### Internationalization
  - **Maintenance.properties**: Added `Maintenance.modifier.obsolete`
  - **Parts.properties**: Added `Part.modifier.obsolete`

  ## Dependencies
  - Requires MegaMek PR with Obsolete quirk implementation (provides `Entity.getObsoleteRepairModifier()` and
  `Entity.getObsoleteResaleModifier()`)

  ## Test Plan
  - [ ] Load campaign with unit that has Obsolete quirk set
  - [ ] Verify maintenance rolls show "obsolete" modifier in TN breakdown
  - [ ] Verify repair rolls show "obsolete" modifier in TN breakdown
  - [ ] Verify unit sell value is reduced based on years obsolete
  - [ ] Test with Infantry units (uses different sell value calculation)

Author: HammerGS

MekHQ/resources/mekhq/resources/Maintenance.properties

@@ -33,3 +33,5 @@ Maintenance.unableToMaintain={0}<b>Warning:</b>{1} {2} has realized they don''t
   This unit should be immediately reassigned to another tech, or maintenance time should be reduced.
 Maintenance.largeVessel={0}<b>Warning:</b>{1} {2} has realized they don''t have enough time to maintain {3}. \
   Maintenance time should be immediately reduced.
+# Modifier descriptions
+Maintenance.modifier.obsolete=obsolete

MekHQ/resources/mekhq/resources/Parts.properties

@@ -49,3 +49,5 @@ PartRepairType.MEK_LOCATION.text=Locations
 PartRepairType.PHYSICAL_WEAPON.text=Physical Weapon
 PartRepairType.POD_SPACE.text=Pod
 PartRepairType.UNKNOWN_LOCATION.text=Error: Unknown Repair Type
+# Modifier descriptions
+Part.modifier.obsolete=obsolete

MekHQ/src/mekhq/campaign/parts/Part.java

@@ -33,6 +33,8 @@
  */
 package mekhq.campaign.parts;
 
+import static mekhq.utilities.MHQInternationalization.getFormattedTextAt;
+
 import java.io.PrintWriter;
 import java.text.DecimalFormat;
 import java.util.ArrayList;
@@ -104,6 +106,7 @@
  */
 public abstract class Part implements IPartWork, ITechnology {
     private static final MMLogger LOGGER = MMLogger.create(Part.class);
+    private static final String RESOURCE_BUNDLE = "mekhq.resources.Parts";
 
     private static final DecimalFormat TONNAGE_FORMATTER = new DecimalFormat("0.#");
 
@@ -975,6 +978,13 @@ public TargetRoll getAllMods(final @Nullable Person tech) {
                 mods.addModifier(1, "difficult to maintain");
             }
 
+            // Apply obsolete quirk modifier
+            int obsoleteMod = getUnit().getEntity().getObsoleteRepairModifier(campaign.getGameYear());
+            if (obsoleteMod > 0) {
+                mods.addModifier(obsoleteMod,
+                      getFormattedTextAt(RESOURCE_BUNDLE, "Part.modifier.obsolete"));
+            }
+
             if (getUnit().hasPrototypeTSM() &&
                       ((this instanceof MekLocation) ||
                              (this instanceof MissingMekLocation) ||
@@ -1033,6 +1043,13 @@ public TargetRoll getAllModsForMaintenance() {
             mods.addModifier(1, "difficult to maintain");
         }
 
+        // Apply obsolete quirk modifier
+        int obsoleteMod = getUnit().getEntity().getObsoleteRepairModifier(campaign.getGameYear());
+        if (obsoleteMod > 0) {
+            mods.addModifier(obsoleteMod,
+                  getFormattedTextAt(RESOURCE_BUNDLE, "Part.modifier.obsolete"));
+        }
+
         if (getUnit().getTech() != null) {
             if (getUnit().getTech().getOptions().booleanOption(PersonnelOptions.TECH_WEAPON_SPECIALIST) &&
                       ((IPartWork.findCorrectRepairType(this) == PartRepairType.WEAPON) ||

MekHQ/src/mekhq/campaign/unit/Maintenance.java

@@ -420,6 +420,16 @@ public static TargetRoll getTargetForMaintenance(Campaign campaign, IPartWork pa
 
         target.append(partWork.getAllModsForMaintenance());
 
+        // Apply obsolete quirk modifier
+        Unit unit = partWork.getUnit();
+        if (unit != null && unit.getEntity() != null) {
+            int obsoleteMod = unit.getEntity().getObsoleteRepairModifier(campaign.getGameYear());
+            if (obsoleteMod > 0) {
+                target.addModifier(obsoleteMod,
+                      getFormattedTextAt(RESOURCE_BUNDLE, "Maintenance.modifier.obsolete"));
+            }
+        }
+
         if (campaignOptions.isUseEraMods()) {
             target.addModifier(campaign.getFaction().getEraMod(campaign.getGameYear()), "era");
         }

MekHQ/src/mekhq/campaign/unit/Unit.java

@@ -1459,14 +1459,22 @@ public Money getSellValue() {
             Money unitCost = Money.of(entity.getAlternateCost());
             double[] usedPartPriceMultipliers = campaign.getCampaignOptions().getUsedPartPriceMultipliers();
 
-            return switch (this.getQuality()) {
+            Money infantryValue = switch (this.getQuality()) {
                 case QUALITY_A -> unitCost.multipliedBy(usedPartPriceMultipliers[0]);
                 case QUALITY_B -> unitCost.multipliedBy(usedPartPriceMultipliers[1]);
                 case QUALITY_C -> unitCost.multipliedBy(usedPartPriceMultipliers[2]);
                 case QUALITY_D -> unitCost.multipliedBy(usedPartPriceMultipliers[3]);
                 case QUALITY_E -> unitCost.multipliedBy(usedPartPriceMultipliers[4]);
                 case QUALITY_F -> unitCost.multipliedBy(usedPartPriceMultipliers[5]);
             };
+
+            // Apply obsolete quirk resale modifier
+            double obsoleteMult = entity.getObsoleteResaleModifier(campaign.getGameYear());
+            if (obsoleteMult < 1.0) {
+                infantryValue = infantryValue.multipliedBy(obsoleteMult);
+            }
+
+            return infantryValue;
         }
 
         // We need to adjust this for equipment that doesn't show up as parts
@@ -1553,6 +1561,12 @@ public Money getSellValue() {
         // Scale the final value by the entity's price multiplier
         partsValue = partsValue.multipliedBy(entity.getPriceMultiplier());
 
+        // Apply obsolete quirk resale modifier
+        double obsoleteMult = entity.getObsoleteResaleModifier(campaign.getGameYear());
+        if (obsoleteMult < 1.0) {
+            partsValue = partsValue.multipliedBy(obsoleteMult);
+        }
+
         return partsValue;
     }