Improper singletons migration to clean Meyer's singletons (cherry-pick) (#2082)

# Pull Request

- Applies the clean and corrected singletons, Meyer pattern. (cherry
picked from @SmashingQuasar )

Testing by just playing the game in various ways. Been tested by myself
@Celandriel and @SmashingQuasar
---

## 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**)

---

## 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
- [x] Documentation updated if needed

---

## Notes for Reviewers

Anything that significantly improves realism at the cost of stability or
performance should be carefully discussed
before merging.

---------

Co-authored-by: Nicolas Lebacq <nicolas.cordier@outlook.com>
Co-authored-by: Keleborn <22352763+Celandriel@users.noreply.github.com>

src/Ai/Base/Trigger/HealthTriggers.h

@@ -48,7 +48,7 @@ class LowHealthTrigger : public HealthInRangeTrigger
 {
 public:
     LowHealthTrigger(PlayerbotAI* botAI, std::string const name = "low health",
-                     float value = sPlayerbotAIConfig->lowHealth, float minValue = 0)
+                     float value = sPlayerbotAIConfig.lowHealth, float minValue = 0)
         : HealthInRangeTrigger(botAI, name, value, minValue)
     {
     }
@@ -60,7 +60,7 @@ class CriticalHealthTrigger : public LowHealthTrigger
 {
 public:
     CriticalHealthTrigger(PlayerbotAI* botAI)
-        : LowHealthTrigger(botAI, "critical health", sPlayerbotAIConfig->criticalHealth, 0)
+        : LowHealthTrigger(botAI, "critical health", sPlayerbotAIConfig.criticalHealth, 0)
     {
     }
 };
@@ -69,7 +69,7 @@ class MediumHealthTrigger : public LowHealthTrigger
 {
 public:
     MediumHealthTrigger(PlayerbotAI* botAI)
-        : LowHealthTrigger(botAI, "medium health", sPlayerbotAIConfig->mediumHealth, 0)
+        : LowHealthTrigger(botAI, "medium health", sPlayerbotAIConfig.mediumHealth, 0)
     {
     }
 };
@@ -78,8 +78,8 @@ class AlmostFullHealthTrigger : public LowHealthTrigger
 {
 public:
     AlmostFullHealthTrigger(PlayerbotAI* botAI)
-        : LowHealthTrigger(botAI, "almost full health", sPlayerbotAIConfig->almostFullHealth,
-                           sPlayerbotAIConfig->mediumHealth)
+        : LowHealthTrigger(botAI, "almost full health", sPlayerbotAIConfig.almostFullHealth,
+                           sPlayerbotAIConfig.mediumHealth)
     {
     }
 };
@@ -88,7 +88,7 @@ class PartyMemberLowHealthTrigger : public HealthInRangeTrigger
 {
 public:
     PartyMemberLowHealthTrigger(PlayerbotAI* botAI, std::string const name = "party member low health",
-                                float value = sPlayerbotAIConfig->lowHealth,
+                                float value = sPlayerbotAIConfig.lowHealth,
                                 float minValue = 0)
         : HealthInRangeTrigger(botAI, name, value, minValue)
     {
@@ -101,7 +101,7 @@ class PartyMemberCriticalHealthTrigger : public PartyMemberLowHealthTrigger
 {
 public:
     PartyMemberCriticalHealthTrigger(PlayerbotAI* botAI)
-        : PartyMemberLowHealthTrigger(botAI, "party member critical health", sPlayerbotAIConfig->criticalHealth, 0)
+        : PartyMemberLowHealthTrigger(botAI, "party member critical health", sPlayerbotAIConfig.criticalHealth, 0)
     {
     }
 };
@@ -110,7 +110,7 @@ class PartyMemberMediumHealthTrigger : public PartyMemberLowHealthTrigger
 {
 public:
     PartyMemberMediumHealthTrigger(PlayerbotAI* botAI)
-        : PartyMemberLowHealthTrigger(botAI, "party member medium health", sPlayerbotAIConfig->mediumHealth,
+        : PartyMemberLowHealthTrigger(botAI, "party member medium health", sPlayerbotAIConfig.mediumHealth,
                                       0)
     {
     }
@@ -120,7 +120,7 @@ class PartyMemberAlmostFullHealthTrigger : public PartyMemberLowHealthTrigger
 {
 public:
     PartyMemberAlmostFullHealthTrigger(PlayerbotAI* botAI)
-        : PartyMemberLowHealthTrigger(botAI, "party member almost full health", sPlayerbotAIConfig->almostFullHealth,
+        : PartyMemberLowHealthTrigger(botAI, "party member almost full health", sPlayerbotAIConfig.almostFullHealth,
                                       0)
     {
     }