feat(simulate): record the CI pipeline a run came from

cmd/lk/simulate.go

@@ -561,6 +561,34 @@
 	})
 }
 
+// ciFromEnv reports the pipeline that started this run, so the dashboard can
+// link a run back to it. GitHub Actions is the only provider recognized; nil
+// means the run did not come from one.
+func ciFromEnv() *livekit.SimulationRun_CI {
+	if os.Getenv("GITHUB_ACTIONS") == "" {
+		return nil
+	}
+	// On a pull_request event GITHUB_REF_NAME is "<number>/merge", which names
+	// neither a branch nor a tag; the head ref is the branch under test.
+	ref := os.Getenv("GITHUB_REF_NAME")
+	if head := os.Getenv("GITHUB_HEAD_REF"); head != "" {
+		ref = head
+	}
+	var pullRequest string
+	if gitRef := os.Getenv("GITHUB_REF"); strings.HasPrefix(gitRef, "refs/pull/") {
+		pullRequest, _, _ = strings.Cut(strings.TrimPrefix(gitRef, "refs/pull/"), "/")
+	}
+	return &livekit.SimulationRun_CI{
+		Provider:    "github_actions",
+		CommitSha:   os.Getenv("GITHUB_SHA"),
+		Ref:         ref,
+		PullRequest: pullRequest,
+		RunUrl: fmt.Sprintf("%s/%s/actions/runs/%s",
+			os.Getenv("GITHUB_SERVER_URL"), os.Getenv("GITHUB_REPOSITORY"), os.Getenv("GITHUB_RUN_ID")),
+		Actor: os.Getenv("GITHUB_ACTOR"),
+	}
+}
+
 func createSimulationRun(ctx context.Context, c *simulateConfig) (string, *livekit.PresignedPostRequest, error) {
 	req := &livekit.SimulationRun_Create_Request{
 		AgentName:            c.agentName,
@@ -569,6 +597,7 @@
 		BackgroundNoise:      c.backgroundNoise,
 		LowQualityMicrophone: c.lowQualityMicrophone,
 		PacketLoss:           c.packetLoss,
+		Ci:                   ciFromEnv(),
 	}
 	if c.concurrency > 0 {
 		req.Concurrency = &c.concurrency

cmd/lk/simulate_ci_env_test.go

@@ -0,0 +1,62 @@
+// Copyright 2026 LiveKit, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package main
+
+import "testing"
+
+func TestCIFromEnvOutsideGitHubActions(t *testing.T) {
+	t.Setenv("GITHUB_ACTIONS", "")
+	if ci := ciFromEnv(); ci != nil {
+		t.Fatalf("expected no CI source, got %v", ci)
+	}
+}
+
+func TestCIFromEnvPullRequest(t *testing.T) {
+	t.Setenv("GITHUB_ACTIONS", "true")
+	t.Setenv("GITHUB_SHA", "abc123")
+	t.Setenv("GITHUB_REF", "refs/pull/42/merge")
+	t.Setenv("GITHUB_REF_NAME", "42/merge")
+	t.Setenv("GITHUB_HEAD_REF", "jason/feature")
+	t.Setenv("GITHUB_SERVER_URL", "https://github.com")
+	t.Setenv("GITHUB_REPOSITORY", "livekit/e2e")
+	t.Setenv("GITHUB_RUN_ID", "77")
+	t.Setenv("GITHUB_ACTOR", "u9g")
+
+	ci := ciFromEnv()
+	if ci.GetPullRequest() != "42" {
+		t.Errorf("pull request: got %q, want %q", ci.GetPullRequest(), "42")
+	}
+	if ci.GetRef() != "jason/feature" {
+		t.Errorf("ref: got %q, want %q", ci.GetRef(), "jason/feature")
+	}
+	if want := "https://github.com/livekit/e2e/actions/runs/77"; ci.GetRunUrl() != want {
+		t.Errorf("run url: got %q, want %q", ci.GetRunUrl(), want)
+	}
+}
+
+func TestCIFromEnvBranchPush(t *testing.T) {
+	t.Setenv("GITHUB_ACTIONS", "true")
+	t.Setenv("GITHUB_REF", "refs/heads/main")
+	t.Setenv("GITHUB_REF_NAME", "main")
+	t.Setenv("GITHUB_HEAD_REF", "")
+
+	ci := ciFromEnv()
+	if ci.GetRef() != "main" {
+		t.Errorf("ref: got %q, want %q", ci.GetRef(), "main")
+	}
+	if ci.GetPullRequest() != "" {
+		t.Errorf("pull request: got %q, want empty", ci.GetPullRequest())
+	}
+}