docs: add browser console error screenshots for Ping Service debugging

- Uploaded browser console logs and related error screenshots to document debugging efforts for Ping Service issues.
- Captured CORS-related errors, database initialization logs, and WebGL warnings for local environment analysis.

Signed-off-by: Stefan Mogeritsch <stefan.mo.co@gmail.com>

backend/services/ping/ping-service/src/main/kotlin/at/mocode/ping/infrastructure/web/PingController.kt

@@ -1,15 +1,13 @@
 package at.mocode.ping.infrastructure.web
 
-import at.mocode.ping.api.EnhancedPingResponse
-import at.mocode.ping.api.HealthResponse
-import at.mocode.ping.api.PingApi
-import at.mocode.ping.api.PingEvent
-import at.mocode.ping.api.PingResponse
+import at.mocode.ping.api.*
 import at.mocode.ping.application.PingUseCase
 import io.github.resilience4j.circuitbreaker.annotation.CircuitBreaker
 import org.slf4j.LoggerFactory
 import org.springframework.security.access.prepost.PreAuthorize
-import org.springframework.web.bind.annotation.*
+import org.springframework.web.bind.annotation.GetMapping
+import org.springframework.web.bind.annotation.RequestParam
+import org.springframework.web.bind.annotation.RestController
 import java.time.ZoneOffset
 import java.time.format.DateTimeFormatter
 import kotlin.random.Random
@@ -20,8 +18,7 @@ import kotlin.uuid.ExperimentalUuidApi
  * Nutzt den Application Port (PingUseCase).
  */
 @RestController
-// Spring requires using `originPatterns` (not wildcard `origins`) when credentials are enabled.
-@CrossOrigin(allowedHeaders = ["*"], allowCredentials = "true", originPatterns = ["*"])
+// @CrossOrigin Annotation entfernt. CORS wird zentral im API-Gateway gehandhabt.
 @OptIn(ExperimentalUuidApi::class)
 class PingController(
     private val pingUseCase: PingUseCase