feat(orchestrator): add concurrent sandbox creation benchmark (#2280)

* feat(orchestrator): add concurrent sandbox creation benchmark

The current maxStartingInstancesPerNode limit of 3 was established from
non-rigorous historical measurements on n1 machines. To find the optimal
limit for n2 machines we need proper data.

This adds BenchmarkConcurrentResume which launches N sandboxes
simultaneously via barrier-synchronized goroutines and measures
per-sandbox creation latency (avg, P50, P95, P99, min, max),
wall-clock time, and success/failure counts.

Concurrency levels default to 1,2,3,4,5,6,7,8,9,10 and can be overridden
via the CONCURRENCY_LEVELS env var. Network and NBD pool sizes are
scaled to the max concurrency level to avoid measuring pool starvation
instead of actual creation overhead.

* feat(orchestrator): use real cgroup manager in concurrent benchmark

Replace cgroup.NewNoopManager() with the real cgroup.NewManager() so
sandboxes get proper CPU and memory isolation via cgroupv2, matching
production behavior.

* feat(orchestrator): aggregate latency stats across benchmark iterations

Accumulate per-sandbox latencies and wall-clock times across all
benchmark iterations instead of reporting only the last iteration.
This makes percentiles (P50/P95/P99) statistically meaningful at
high iteration counts (e.g. -benchtime=100x at concurrency-5 gives
500 latency samples instead of 5).

* feat(orchestrator): add awk script to convert benchmark results to markdown table

* fix(orchestrator): fix linter issues in concurrent benchmark

- Use max/min builtins instead of if-chains in percentile()
- Use WaitGroup.Go instead of manual Add/Done goroutine pattern
- Replace sort.Slice/sort.Ints with slices.Sort
- Add blank line before bare return (nlreturn)
- Rename min/max variables to fastest/slowest to avoid shadowing builtins

* chore(orchestrator): rename bench2md.awk to benchmark-to-markdown.awk

Use a more descriptive filename for the awk script that converts
Go benchmark output to markdown tables.

* refactor(orchestrator): move benchmark tests to benchmarks/ folder

Keep benchmark files in a dedicated subdirectory to separate them
from the main orchestrator source. Update relative paths to account
for the extra directory level.

* chore: auto-commit generated changes

---------

Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>

Author: arkamar

packages/orchestrator/benchmark_test.go …rchestrator/benchmarks/benchmark_test.gopackages/orchestrator/benchmark_test.go renamed to packages/orchestrator/benchmarks/benchmark_test.go packages/orchestrator/benchmark_test.go renamed to packages/orchestrator/benchmarks/benchmark_test.go

@@ -47,7 +47,7 @@ import (
 	"github.com/e2b-dev/infra/packages/shared/pkg/utils"
 )
 
-var tracer = otel.Tracer("github.com/e2b-dev/infra/packages/orchestrator")
+var tracer = otel.Tracer("github.com/e2b-dev/infra/packages/orchestrator/benchmarks")
 
 func BenchmarkBaseImageLaunch(b *testing.B) {
 	if os.Geteuid() != 0 {
@@ -106,8 +106,8 @@ func BenchmarkBaseImageLaunch(b *testing.B) {
 
 	// hacks, these should go away
 	b.Setenv("ARTIFACTS_REGISTRY_PROVIDER", "Local")
-	b.Setenv("FIRECRACKER_VERSIONS_DIR", abs(filepath.Join("..", "fc-versions", "builds")))
-	b.Setenv("HOST_ENVD_PATH", abs(filepath.Join("..", "envd", "bin", "envd")))
+	b.Setenv("FIRECRACKER_VERSIONS_DIR", abs(filepath.Join("..", "..", "fc-versions", "builds")))
+	b.Setenv("HOST_ENVD_PATH", abs(filepath.Join("..", "..", "envd", "bin", "envd")))
 	b.Setenv("HOST_KERNELS_DIR", abs(kernelsDir))
 	b.Setenv("LOCAL_TEMPLATE_STORAGE_BASE_PATH", abs(filepath.Join(persistenceDir, "templates")))
 	b.Setenv("ORCHESTRATOR_BASE_PATH", tempDir)