Add integration test framework: plan, workload binary, harness scaffolding

- INTEGRATIONTESTS-PLAN.md: full design for e2e integration tests
- integrationtests/cmd/ioworkload: standalone binary with 13 I/O scenarios
- integrationtests/expectations.go: ExpectedEvent type and assertion helpers
- integrationtests/parse.go: .ior.zst parser producing TestResult
- Export IterRecord and LoadFromFile in flamegraph package
- Fix TraceId -> TraceID, StringByName returns error instead of panic

Amp-Thread-ID: https://ampcode.com/threads/T-019c8031-c106-757a-95a0-7a5457163ce7
Co-authored-by: Amp <amp@ampcode.com>

1 files changed, 25 insertions, 0 deletions

diff --git a/integrationtests/parse.go b/integrationtests/parse.go
new file mode 100644
index 0000000..cebb0ba
--- /dev/null
+++ b/integrationtests/parse.go
@@ -0,0 +1,25 @@
+package integrationtests
+
+import (
+	"fmt"
+	"ior/internal/flamegraph"
+)
+
+// TestResult holds all captured I/O records from a single ior run.
+type TestResult struct {
+	Records []flamegraph.IterRecord
+}
+
+// LoadTestResult parses an .ior.zst file into a TestResult.
+func LoadTestResult(iorZstFile string) (TestResult, error) {
+	iter, err := flamegraph.LoadFromFile(iorZstFile)
+	if err != nil {
+		return TestResult{}, fmt.Errorf("load test result: %w", err)
+	}
+
+	var result TestResult
+	for record := range iter {
+		result.Records = append(result.Records, record)
+	}
+	return result, nil
+}