Big Water-Nukes Performance Improvements 💧 (#3668)

## Description:

### 1. Water Magnitude Calculation Optimization (WaterManager.ts)
* Boxed BFS Approach: Refactored the water magnitude recomputation to
use "Dirty" and "Seed" boxes. Instead of a global update, the system now
only recalculates magnitudes within a specific radius of the affected
area, significantly reducing CPU load after water-nuke-explosions
* Shoreline Bit Optimization: Narrowed the scope for updating shoreline
bits to a 2-ring neighborhood around converted tiles, avoiding
unnecessary checks across the entire map.

Performance test on the world map:
- AtomBomb (r=30): 24ms (was 344ms with global BFS), 2,993 changed tiles
(was 630k)
- Massive (r=200): 178ms (was 378ms), 130k changed tiles (was 654k)

### 2. Pathfinding Rebuild Staggering (PathFinder.ts,
TradeShipExecution.ts, TransportShipExecution.ts)
* Distributed Rebuilds: Introduced a staggering mechanism in
WaterPathFinder. Ship pathfinders now wait a randomized/distributed
number of ticks (0 - 5 seconds) before rebuilding after a water graph
change.
* CPU Spike Mitigation: By spreading out these expensive A* rebuilds
over time, we prevent lag when hundreds of ships attempt to re-path
simultaneously
* Like Mole said it: "Pretty realistic I;d say the capitan needs a
second to realize the big nuke on the left opened a new path"

From a performance test on the big new Luna map:
Graph rebuild: 256.4ms
Pathfinder-Rebuild of 329 ships (Including other Executions): 1564.4ms
(No longer noticeable, spread over 5s)

###  3. Performance Refinements
* Simplified deep ocean magnitude logic within the optimized BFS flow.
   * Improved memory efficiency by utilizing clipped BFS wavefronts.

## 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:

FloPinguin

src/core/execution/TradeShipExecution.ts

@@ -22,6 +22,8 @@ export class TradeShipExecution implements Execution {
   private motionPlanId = 1;
   private motionPlanDst: TileRef | null = null;
 
+  private static _staggerCounter = 0;
+
   constructor(
     private origOwner: Player,
     private srcPort: Unit,
@@ -30,7 +32,9 @@ export class TradeShipExecution implements Execution {
 
   init(mg: Game, ticks: number): void {
     this.mg = mg;
-    this.pathFinder = new WaterPathFinder(mg);
+    const stagger =
+      TradeShipExecution._staggerCounter++ % WaterPathFinder.STAGGER_SPREAD;
+    this.pathFinder = new WaterPathFinder(mg, stagger);
   }
 
   tick(ticks: number): void {

src/core/execution/TransportShipExecution.ts

@@ -29,6 +29,8 @@ export class TransportShipExecution implements Execution {
   private target: Player | TerraNullius;
   private pathFinder: WaterPathFinder;
 
+  private static _staggerCounter = 0;
+
   private dst: TileRef | null;
   private src: TileRef | null;
   private retreatDst: TileRef | false | null = null;
@@ -60,7 +62,9 @@ export class TransportShipExecution implements Execution {
     this.lastMove = ticks;
     this.mg = mg;
     this.target = mg.owner(this.ref);
-    this.pathFinder = new WaterPathFinder(mg);
+    const stagger =
+      TransportShipExecution._staggerCounter++ % WaterPathFinder.STAGGER_SPREAD;
+    this.pathFinder = new WaterPathFinder(mg, stagger);
 
     if (
       this.attacker.unitCount(UnitType.TransportShip) >=