ADFA-4128 (6/11): address CodeRabbit review

- F1718-2 stop advertising an E2eTimeline.parse that does not exist
- F1718-6 stop the metrics helper swallowing fatals and cancellation
- F1718-7 drop the dead telemetry.report import from LiveReloadOrchestratorTest
- F1718-8 cover queueMillis in the HostSpans per-field test

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01FstXxJ5cwWPcvmhZ9vJgJ7

Author: fryanpan

quickbuild/core/src/main/java/org/appdevforall/cotg/quickbuild/domain/telemetry/README.md

@@ -4,5 +4,5 @@ Pure-JVM types for measuring the live-reload loop: one timeline per edit and one
 
 | File | Purpose |
 | --- | --- |
-| [`E2eTimeline.kt`](E2eTimeline.kt) | One generation's four-stamp timeline plus `StepTimings`, `HostSpans`, `BuildCounts`; derives stage deltas and the grep-stable log `format`/`parse`. |
+| [`E2eTimeline.kt`](E2eTimeline.kt) | One generation's four-stamp timeline plus `StepTimings`, `HostSpans`, `BuildCounts`; derives stage deltas and the grep-stable log `format`. Nothing here parses that line back - the benchmark harness's own Python parser does. |
 | [`QuickBuildMetricsSink.kt`](QuickBuildMetricsSink.kt) | Interface for recording session/build/invalidation/reload/rebuild stats; must be cheap and never throw. Includes a `Noop` implementation. |

quickbuild/core/src/main/java/org/appdevforall/cotg/quickbuild/service/telemetry/MetricsReporting.kt

@@ -1,5 +1,6 @@
 package org.appdevforall.cotg.quickbuild.service.telemetry
 
+import kotlinx.coroutines.CancellationException
 import org.slf4j.Logger
 import org.slf4j.LoggerFactory
 
@@ -13,12 +14,24 @@ internal val metricsLog: Logger = LoggerFactory.getLogger("QB-Metrics")
  * Every metrics call in this package goes through here rather than relying on each class
  * to remember its own try/catch.
  *
+ * Two kinds of throwable are NOT swallowed - see the catch clauses for why.
+ *
  * @param block the metrics call; must be side-effect-free beyond reporting, since a
  *   partial run is swallowed and never retried
  */
 internal inline fun report(block: () -> Unit) {
 	try {
 		block()
+	} catch (e: CancellationException) {
+		// This helper is inline, so a suspending call written inside the lambda compiles.
+		// Swallowing its cancellation would run the caller's coroutine on past its own
+		// cancellation, and nothing warns the author - there is no compile error to hit.
+		throw e
+	} catch (e: VirtualMachineError) {
+		// The VM is out of a resource the rest of the build also needs. Logging it formats a
+		// message and walks a stack trace, and the build then carries on reporting Success -
+		// hiding the failure on exactly the low-spec devices this product exists for.
+		throw e
 	} catch (e: Throwable) {
 		metricsLog.warn("Quick Build metrics sink failed", e)
 	}

quickbuild/core/src/test/java/org/appdevforall/cotg/quickbuild/domain/reload/LiveReloadOrchestratorTest.kt

@@ -11,7 +11,6 @@ import org.appdevforall.cotg.quickbuild.domain.ChangedFiles
 import org.appdevforall.cotg.quickbuild.domain.classify.BuildRoute
 import org.appdevforall.cotg.quickbuild.domain.classify.ChangeClassifier
 import org.appdevforall.cotg.quickbuild.domain.classify.InvalidationReason
-import org.appdevforall.cotg.quickbuild.service.telemetry.report
 import org.junit.jupiter.api.Test
 import java.io.File
 

quickbuild/core/src/test/java/org/appdevforall/cotg/quickbuild/domain/telemetry/E2eTimelineGroupsTest.kt

@@ -57,6 +57,7 @@ class E2eTimelineGroupsTest {
 	fun `each HostSpans field alone makes the group non-empty and counts toward the total`() {
 		val singles =
 			listOf(
+				E2eTimeline.HostSpans(queueMillis = 7),
 				E2eTimeline.HostSpans(scanMillis = 7),
 				E2eTimeline.HostSpans(compileRpcMillis = 7),
 				E2eTimeline.HostSpans(policyMillis = 7),

quickbuild/core/src/test/java/org/appdevforall/cotg/quickbuild/service/telemetry/MetricsReportingTest.kt

@@ -0,0 +1,46 @@
+package org.appdevforall.cotg.quickbuild.service.telemetry
+
+import com.google.common.truth.Truth.assertThat
+import kotlinx.coroutines.CancellationException
+import org.junit.jupiter.api.Test
+import org.junit.jupiter.api.assertThrows
+
+/**
+ * What [report] may and may not swallow. A metrics sink must never break a build, but two
+ * throwables are not the sink's failure to absorb: a [VirtualMachineError] means the whole
+ * process is out of a resource, and a [CancellationException] belongs to the caller's
+ * coroutine - [report] is `inline`, so a suspending call written inside the lambda compiles
+ * with no warning that its cancellation would be eaten here.
+ */
+class MetricsReportingTest {
+	@Test
+	fun `an ordinary sink failure is swallowed`() {
+		var ran = false
+
+		report {
+			ran = true
+			throw IllegalStateException("sink is down")
+		}
+
+		// No throw: the build carries on, which is the whole point of the helper.
+		assertThat(ran).isTrue()
+	}
+
+	@Test
+	fun `a VirtualMachineError is not swallowed`() {
+		val fatal = OutOfMemoryError("no heap left for the metrics buffer")
+
+		val thrown = assertThrows<OutOfMemoryError> { report { throw fatal } }
+
+		assertThat(thrown).isSameInstanceAs(fatal)
+	}
+
+	@Test
+	fun `a CancellationException reaches the caller's coroutine`() {
+		val cancelled = CancellationException("session torn down mid-report")
+
+		val thrown = assertThrows<CancellationException> { report { throw cancelled } }
+
+		assertThat(thrown).isSameInstanceAs(cancelled)
+	}
+}