fix(PlayerExecution): remove alarming DefensePost destruction messages on capture (#2163)

## Description:

Patches issue flagged from
https://github.com/openfrontio/OpenFrontIO/pull/1957#issuecomment-3386398998.

Right now for every single defense post capture, attackers receive two
messages:
- "Your Defense Post was destroyed" and "Captured Defense Post from ..."

By downgrading before captures, behavior will now be:
- defender receives "Your Defense Post was destroyed"
- attacker receives no message unless capturing a lv2+ defense post
(downgraded to lv 1), in which case they receive "Captured Defense Post
from ..."

## Please complete the following:

- [X] I have added screenshots for all UI updates
- [X] I process any text displayed to the user through translateText()
and I've added it to the en.json file
- [X] I have added relevant tests to the test directory
- [X] I confirm I have thoroughly tested these changes and take full
responsibility for any bugs introduced

## Please put your Discord username so you can be contacted if a bug or
regression is found:

`seekerreturns`

---------

Co-authored-by: evanpelle <evanpelle@gmail.com>

src/core/execution/PlayerExecution.ts

@@ -27,23 +27,30 @@ export class PlayerExecution implements Execution {
 
   tick(ticks: number) {
     this.player.decayRelations();
-    this.player.units().forEach((u) => {
-      const tileOwner = this.mg!.owner(u.tile());
-      if (u.info().territoryBound) {
-        if (tileOwner?.isPlayer()) {
-          if (tileOwner !== this.player) {
-            if (u.type() === UnitType.DefensePost) {
-              this.mg!.player(tileOwner.id()).captureUnit(u);
-              u.decreaseLevel(this.mg!.player(tileOwner.id()));
-            } else {
-              this.mg!.player(tileOwner.id()).captureUnit(u);
-            }
-          }
-        } else {
-          u.delete();
-        }
+    for (const u of this.player.units()) {
+      if (!u.info().territoryBound) {
+        continue;
       }
-    });
+
+      const owner = this.mg!.owner(u.tile());
+      if (!owner?.isPlayer()) {
+        u.delete();
+        continue;
+      }
+      if (owner === this.player) {
+        continue;
+      }
+
+      const captor = this.mg!.player(owner.id());
+      if (u.type() === UnitType.DefensePost) {
+        u.decreaseLevel(captor);
+        if (u.isActive()) {
+          captor.captureUnit(u);
+        }
+      } else {
+        captor.captureUnit(u);
+      }
+    }
 
     if (!this.player.isAlive()) {
       // Player has no tiles, delete any remaining units and gold