Trading in lakes 🚤 (#3653)

## Description:

- Widened port placement and warship spawn/patrol checks from
`isOcean`/`isOceanShore` to `isWater`/`isShore`, so ports can be built
on lake shores and ships can operate on lakes, we discussed it here:

<img width="996" height="423" alt="image"
src="https://github.com/user-attachments/assets/acf1e970-9631-4848-a0ed-6d0470616e1d"
/>

- Filtered `tradingPorts()` by water component so ports only attempt
trades with reachable ports - prevents silent path-not-found failures
across disconnected water bodies
- Applied the same water component filter when a captured trade ship
reroutes to its new owner's nearest port
- Removed the `WaterManager` fallback that force-marked isolated
water-nuked-tiles as ocean (no longer needed since lakes are now
navigable)
- Added a check to prevent nations from building ports on water bodies
that aren't accessible to other players

## 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

---------

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

src/client/graphics/layers/UnitLayer.ts

@@ -137,7 +137,7 @@ export class UnitLayer implements Layer {
 
       clickRef = this.game.ref(cell.x, cell.y);
     }
-    if (!this.game.isOcean(clickRef)) return;
+    if (!this.game.isWater(clickRef)) return;
 
     if (this.selectedUnit) {
       this.eventBus.emit(
@@ -169,13 +169,13 @@ export class UnitLayer implements Layer {
     const clickRef = this.game.ref(cell.x, cell.y);
     if (this.game.inSpawnPhase()) {
       // No Radial Menu during spawn phase, only spawn point selection
-      if (!this.game.isOcean(clickRef)) {
+      if (!this.game.isWater(clickRef)) {
         this.eventBus.emit(new MouseUpEvent(event.x, event.y));
       }
       return;
     }
 
-    if (!this.game.isOcean(clickRef)) {
+    if (!this.game.isWater(clickRef)) {
       // No warship to find because no Ocean tile, open Radial Menu
       this.eventBus.emit(new ContextMenuEvent(event.x, event.y));
       return;