Stage2 refactor switch custom calculations by core helpers clean (#2127)

# Pull Request

This change replaces a few manual distance calculations in
`WorldPosition` with AzerothCore distance helpers. The goal is to reduce
duplicated math, keep behavior consistent with core utilities, and avoid
reimplementing logic that already exists in the core.

---

## Design Philosophy

We prioritize **stability, performance, and predictability** over
behavioral realism.
Complex player-mimicking logic is intentionally limited due to its
negative impact on scalability, maintainability, and
long-term robustness.

Excessive processing overhead can lead to server hiccups, increased CPU
usage, and degraded performance for all
participants. Because every action and
decision tree is executed **per bot and per trigger**, even small
increases in logic complexity can scale poorly and
negatively affect both players and
world (random) bots. Bots are not expected to behave perfectly, and
perfect simulation of human decision-making is not a
project goal. Increased behavioral
realism often introduces disproportionate cost, reduced predictability,
and significantly higher maintenance overhead.

Every additional branch of logic increases long-term responsibility. All
decision paths must be tested, validated, and
maintained continuously as the system evolves.
If advanced or AI-intensive behavior is introduced, the **default
configuration must remain the lightweight decision
model**. More complex behavior should only be
available as an **explicit opt-in option**, clearly documented as having
a measurable performance cost.

Principles:

- **Stability before intelligence**  
  A stable system is always preferred over a smarter one.

- **Performance is a shared resource**  
  Any increase in bot cost affects all players and all bots.

- **Simple logic scales better than smart logic**  
Predictable behavior under load is more valuable than perfect decisions.

- **Complexity must justify itself**  
  If a feature cannot clearly explain its cost, it should not exist.

- **Defaults must be cheap**  
  Expensive behavior must always be optional and clearly communicated.

- **Bots should look reasonable, not perfect**  
  The goal is believable behavior, not human simulation.

Before submitting, confirm that this change aligns with those
principles.

---

## Feature Evaluation

Please answer the following:

- Describe the **minimum logic** required to achieve the intended
behavior?
Use existing core distance helpers instead of manual math, keeping the
logic localized to `WorldPosition`.
- Describe the **cheapest implementation** that produces an acceptable
result?
Directly call `GetExactDist`, `GetExactDist2d`, and `GetExactDist2dSq`
where appropriate.
- Describe the **runtime cost** when this logic executes across many
bots?
No additional cost; the helper calls replace equivalent math and avoid
extra intermediate objects.

---

## How to Test the Changes

- Step-by-step instructions to test the change
- Build the module and run existing bot scenarios that rely on
`WorldPosition` distance checks.
  - Verify no behavioral regressions in travel-related logic.
- Any required setup (e.g. multiple players, bots, specific
configuration)
  - Standard server + mod-playerbots setup.
- Expected behavior and how to verify it
- Distances computed in travel logic remain identical; no gameplay
change expected.

## Complexity & Impact

Does this change add new decision branches?
- - [x] No
- - [ ] Yes (**explain below**)

Does this change increase per-bot or per-tick processing?
- - [x] No
- - [ ] Yes (**describe and justify impact**)

Could this logic scale poorly under load?
- - [x] No
- - [ ] Yes (**explain why**)
---

## Defaults & Configuration

Does this change modify default bot behavior?
- - [x] No
- - [ ] Yes (**explain why**)

If this introduces more advanced or AI-heavy logic:
- - [x] Lightweight mode remains the default
- - [x] More complex behavior is optional and thereby configurable
---

## AI Assistance

Was AI assistance (e.g. ChatGPT or similar tools) used while working on
this change?
- - [x] No
- - [ ] Yes (**explain below**)

---

## Final Checklist

- - [x] Stability is not compromised
- - [x] Performance impact is understood, tested, and acceptable
- - [x] Added logic complexity is justified and explained
- - [ ] Documentation updated if needed

---

## Notes for Reviewers

This is a localized refactor that replaces manual distance math with
core helpers for consistency and maintainability.
No behavioral change is expected.

---------

Co-authored-by: Keleborn <22352763+Celandriel@users.noreply.github.com>

src/Ai/Base/Actions/RpgSubActions.cpp

@@ -52,14 +52,15 @@ GuidPosition RpgHelper::guidP() { return AI_VALUE(GuidPosition, "rpg target"); }
 
 ObjectGuid RpgHelper::guid() { return (ObjectGuid)guidP(); }
 
-bool RpgHelper::InRange()
-{
-    GuidPosition gp = guidP();
-    if (!gp)
-        return false;
+ bool RpgHelper::InRange()
+ {
+     GuidPosition targetGuid = guidP();
+     if (!targetGuid)
+         return false;
 
-    return gp.sqDistance2d(bot) < INTERACTION_DISTANCE * INTERACTION_DISTANCE;
-}
+    return bot->GetExactDist2dSq(targetGuid.GetPositionX(), targetGuid.GetPositionY()) <
+        INTERACTION_DISTANCE * INTERACTION_DISTANCE;
+ }
 
 void RpgHelper::setFacingTo(GuidPosition guidPosition)
 {