refactor: update meterRegistry usage to Option type and improve formatting

.codesight/CODESIGHT.md

@@ -2,7 +2,7 @@
 
 > **Stack:** raw-http | none | unknown | scala
 
-> 0 routes + 40 rpc | 0 models | 0 components | 163 lib files | 1 env vars | 1 middleware
+> 0 routes + 40 rpc | 0 models | 0 components | 164 lib files | 1 env vars | 1 middleware
 > **Token savings:** this file is ~0 tokens. Without it, AI exploration would cost ~0 tokens. **Saves ~0 tokens per conversation.**
 
 ---
@@ -235,7 +235,7 @@
   - function rebalanceInterval
   - function rebalanceMinInterval
   - function heartbeatTtl
-  - _...11 more_
+  - _...12 more_
 - `modules/coordinator/src/main/scala/de/nowchess/coordinator/config/JacksonConfig.scala` — class JacksonConfig, function customize
 - `modules/coordinator/src/main/scala/de/nowchess/coordinator/config/NativeReflectionConfig.scala` — class NativeReflectionConfig
 - `modules/coordinator/src/main/scala/de/nowchess/coordinator/grpc/CoordinatorGrpcServer.scala` — class CoordinatorGrpcServer
@@ -255,6 +255,7 @@
   - _...1 more_
 - `modules/coordinator/src/main/scala/de/nowchess/coordinator/service/AutoScaler.scala`
   - class AutoScaler
+  - function initMetrics
   - function checkAndScale
   - function scaleUp
   - function scaleDown
@@ -273,12 +274,12 @@
   - function watchK8sPods
 - `modules/coordinator/src/main/scala/de/nowchess/coordinator/service/InstanceRegistry.scala`
   - class InstanceRegistry
+  - function initMetrics
   - function setRedisPrefix
   - function getInstance
   - function getAllInstances
   - function updateInstanceFromRedis
-  - function markInstanceDead
+  - _...3 more_
-  - _...1 more_
 - `modules/coordinator/src/main/scala/de/nowchess/coordinator/service/LoadBalancer.scala`
   - class LoadBalancer
   - function setRedisPrefix
@@ -319,7 +320,7 @@
   - function context
   - function pendingDrawOfferBy
   - function currentClockState
-  - _...21 more_
+  - _...22 more_
 - `modules/core/src/main/scala/de/nowchess/chess/exception/ApiException.scala`
   - class ApiException
   - class GameNotFoundException
@@ -371,6 +372,7 @@
   - function generateId
 - `modules/core/src/main/scala/de/nowchess/chess/registry/RedisGameRegistry.scala`
   - class RedisGameRegistry
+  - function initMetrics
   - function generateId
   - function store
   - function get
@@ -588,6 +590,7 @@
   - _...6 more_
 - `modules/rule/src/main/scala/de/nowchess/rules/sets/DefaultRules.scala` — class DefaultRules, function positionOf
 - `modules/security/src/main/scala/de/nowchess/security/InternalAuthFilter.scala` — class InternalAuthFilter
+- `modules/security/src/main/scala/de/nowchess/security/InternalClientHeadersFactory.scala` — class InternalClientHeadersFactory
 - `modules/security/src/main/scala/de/nowchess/security/InternalGrpcAuthInterceptor.scala` — class InternalGrpcAuthInterceptor
 - `modules/security/src/main/scala/de/nowchess/security/InternalGrpcSecretClientInterceptor.scala` — class InternalGrpcSecretClientInterceptor
 - `modules/security/src/main/scala/de/nowchess/security/InternalSecretClientFilter.scala` — class InternalSecretClientFilter

.codesight/libs.md

@@ -179,7 +179,7 @@
   - function rebalanceInterval
   - function rebalanceMinInterval
   - function heartbeatTtl
-  - _...11 more_
+  - _...12 more_
 - `modules/coordinator/src/main/scala/de/nowchess/coordinator/config/JacksonConfig.scala` — class JacksonConfig, function customize
 - `modules/coordinator/src/main/scala/de/nowchess/coordinator/config/NativeReflectionConfig.scala` — class NativeReflectionConfig
 - `modules/coordinator/src/main/scala/de/nowchess/coordinator/grpc/CoordinatorGrpcServer.scala` — class CoordinatorGrpcServer
@@ -199,6 +199,7 @@
   - _...1 more_
 - `modules/coordinator/src/main/scala/de/nowchess/coordinator/service/AutoScaler.scala`
   - class AutoScaler
+  - function initMetrics
   - function checkAndScale
   - function scaleUp
   - function scaleDown
@@ -217,12 +218,12 @@
   - function watchK8sPods
 - `modules/coordinator/src/main/scala/de/nowchess/coordinator/service/InstanceRegistry.scala`
   - class InstanceRegistry
+  - function initMetrics
   - function setRedisPrefix
   - function getInstance
   - function getAllInstances
   - function updateInstanceFromRedis
-  - function markInstanceDead
+  - _...3 more_
-  - _...1 more_
 - `modules/coordinator/src/main/scala/de/nowchess/coordinator/service/LoadBalancer.scala`
   - class LoadBalancer
   - function setRedisPrefix
@@ -263,7 +264,7 @@
   - function context
   - function pendingDrawOfferBy
   - function currentClockState
-  - _...21 more_
+  - _...22 more_
 - `modules/core/src/main/scala/de/nowchess/chess/exception/ApiException.scala`
   - class ApiException
   - class GameNotFoundException
@@ -315,6 +316,7 @@
   - function generateId
 - `modules/core/src/main/scala/de/nowchess/chess/registry/RedisGameRegistry.scala`
   - class RedisGameRegistry
+  - function initMetrics
   - function generateId
   - function store
   - function get
@@ -532,6 +534,7 @@
   - _...6 more_
 - `modules/rule/src/main/scala/de/nowchess/rules/sets/DefaultRules.scala` — class DefaultRules, function positionOf
 - `modules/security/src/main/scala/de/nowchess/security/InternalAuthFilter.scala` — class InternalAuthFilter
+- `modules/security/src/main/scala/de/nowchess/security/InternalClientHeadersFactory.scala` — class InternalClientHeadersFactory
 - `modules/security/src/main/scala/de/nowchess/security/InternalGrpcAuthInterceptor.scala` — class InternalGrpcAuthInterceptor
 - `modules/security/src/main/scala/de/nowchess/security/InternalGrpcSecretClientInterceptor.scala` — class InternalGrpcSecretClientInterceptor
 - `modules/security/src/main/scala/de/nowchess/security/InternalSecretClientFilter.scala` — class InternalSecretClientFilter

modules/account/src/main/scala/de/nowchess/account/service/AccountService.scala

@@ -61,7 +61,7 @@ class AccountService:
   def login(req: LoginRequest): Either[AccountError, String] =
     val result = authenticateUser(req)
     result match
-      case Right(_)    => meterRegistry.counter("nowchess.auth.logins", "result", "success").increment()
+      case Right(_) => meterRegistry.counter("nowchess.auth.logins", "result", "success").increment()
       case Left(error) =>
         meterRegistry.counter("nowchess.auth.logins", "result", "failure").increment()
         meterRegistry.counter("nowchess.auth.login.failures", "reason", loginFailureReason(error)).increment()

modules/account/src/main/scala/de/nowchess/account/service/ChallengeService.scala

@@ -118,7 +118,11 @@ class ChallengeService:
     result.foreach(_ => meterRegistry.counter("nowchess.challenges.declined").increment())
     result
 
-  private def declineChallenge(challengeId: UUID, userId: UUID, req: DeclineRequest): Either[ChallengeError, Challenge] =
+  private def declineChallenge(
+      challengeId: UUID,
+      userId: UUID,
+      req: DeclineRequest,
+  ): Either[ChallengeError, Challenge] =
     for
       challenge <- challengeRepository.findById(challengeId).toRight(ChallengeError.ChallengeNotFound)
       _         <- Either.cond(challenge.status == ChallengeStatus.Created, (), ChallengeError.ChallengeNotActive)

modules/official-bots/src/main/scala/de/nowchess/bot/logic/AlphaBetaSearch.scala

@@ -15,7 +15,7 @@ final class AlphaBetaSearch(
     tt: TranspositionTable = TranspositionTable(),
     weights: Evaluation,
     numThreads: Int = Runtime.getRuntime.availableProcessors,
-    meterRegistry: MeterRegistry = null,
+    meterRegistry: Option[MeterRegistry] = None,
 ):
 
   private val INF                  = Int.MaxValue / 2
@@ -108,9 +108,10 @@ final class AlphaBetaSearch(
     result
 
   private def recordSearchMetrics(depthReached: Int): Unit =
-    if meterRegistry != null then
+    meterRegistry.foreach { mr =>
-      meterRegistry.summary("nowchess.bot.search.nodes").record(nodeCount.get().toDouble)
+      mr.summary("nowchess.bot.search.nodes").record(nodeCount.get().toDouble)
-      meterRegistry.summary("nowchess.bot.search.depth").record(depthReached.toDouble)
+      mr.summary("nowchess.bot.search.depth").record(depthReached.toDouble)
+    }
 
   private def isOutOfTime: Boolean =
     System.currentTimeMillis - timeStartMs.get >= timeLimitMs.get

modules/official-bots/src/main/scala/de/nowchess/bot/service/OfficialBotService.scala

@@ -19,11 +19,11 @@ import java.util.function.Consumer
 class OfficialBotService:
 
   // scalafix:off DisableSyntax.var
-  @Inject var redis: RedisDataSource         = uninitialized
+  @Inject var redis: RedisDataSource       = uninitialized
-  @Inject var redisConfig: RedisConfig       = uninitialized
+  @Inject var redisConfig: RedisConfig     = uninitialized
-  @Inject var objectMapper: ObjectMapper     = uninitialized
+  @Inject var objectMapper: ObjectMapper   = uninitialized
-  @Inject var botController: BotController   = uninitialized
+  @Inject var botController: BotController = uninitialized
-  @Inject var meterRegistry: MeterRegistry   = uninitialized
+  @Inject var meterRegistry: MeterRegistry = uninitialized
   // scalafix:on DisableSyntax.var
 
   private val terminalStatuses =