test(spring-boot): Move the Boot 3 tracing and HTTP client tests into the module

Ports the jakarta sample's DistributedTracingSystemTest and
TodoSystemTest to the integrationTest suite. The app calls itself on
its random port instead of a hardcoded localhost:8080, and serves the
todo the sample fetched from jsonplaceholder.typicode.com, so the tests
no longer need the internet.

Adds MockSentryServer.assertNoEnvelope for the unsampled case. A flush
can't prove an absence because the server may finish its transaction
after the client already has the response, so it watches for a short
window instead of the old 10s sleep.

The suite declares context-propagation explicitly: without it Reactor
can't carry the Sentry scope to the WebClient's thread. The sample only
had it because Spring GraphQL pulls it in.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

Author: runningcode

sentry-samples/sentry-samples-spring-boot-jakarta/src/test/kotlin/io/sentry/systemtest/DistributedTracingSystemTest.kt

@@ -180,13 +180,20 @@ testing {
         implementation(projects.sentryAsyncProfiler)
         implementation(projects.sentryJdbc)
         implementation(projects.sentryLogback)
+        implementation(projects.sentryOkhttp)
         implementation(projects.sentryTestSupport)
+        // Reactor's automatic context propagation needs it to carry the Sentry scope across
+        // threads.
+        // The sample only had it because Spring GraphQL pulls it in.
+        implementation(libs.context.propagation)
         implementation(libs.kotlin.test.junit)
         implementation(libs.google.truth)
+        implementation(libs.okhttp)
         implementation(libs.springboot3.starter.aop)
         implementation(libs.springboot3.starter.jdbc)
         implementation(libs.springboot3.starter.test)
         implementation(libs.springboot3.starter.web)
+        implementation(libs.springboot3.starter.webflux)
         runtimeOnly(libs.hsqldb)
       }
     }

sentry-samples/sentry-samples-spring-boot-jakarta/src/test/kotlin/io/sentry/systemtest/TodoSystemTest.kt

@@ -0,0 +1,22 @@
+package io.sentry.spring.boot.jakarta.integrationtest
+
+import org.springframework.web.bind.annotation.GetMapping
+import org.springframework.web.bind.annotation.PathVariable
+import org.springframework.web.bind.annotation.PostMapping
+import org.springframework.web.bind.annotation.RequestBody
+import org.springframework.web.bind.annotation.RequestMapping
+import org.springframework.web.bind.annotation.RestController
+import org.springframework.web.client.RestClient
+
+/** Forwards to this app's own Person endpoints, so a trace continues through outgoing requests. */
+@RestController
+@RequestMapping("/tracing/")
+open class DistributedTracingController(private val restClient: RestClient) {
+  @GetMapping("{id}")
+  open fun person(@PathVariable("id") id: Long): Person? =
+    restClient.get().uri(selfUrl("/person/$id")).retrieve().body(Person::class.java)
+
+  @PostMapping
+  open fun create(@RequestBody person: Person): Person? =
+    restClient.post().uri(selfUrl("/person/")).body(person).retrieve().body(Person::class.java)
+}