enhance: log task, job and run identifiers when a task starts (#1257)

Replace the `task N repo is ...` line with a structured `task started` entry carrying `task_id`, `job_id`, `run_id`, `run_number`, `repository` and the workflow's `job` key, so external supervisors can match runner activity to the job in Gitea. `job_id` is read from the runtime token's claims, tokens and secrets are never logged.

Closes https://gitea.com/gitea/runner/issues/752

---------

Co-authored-by: silverwind <[email protected]>
Co-authored-by: silverwind <[email protected]>
Reviewed-on: https://gitea.com/gitea/runner/pulls/1257
Reviewed-by: silverwind <[email protected]>

internal/app/run/runner_test.go

@@ -5,6 +5,7 @@ package run
 
 import (
 	"context"
+	"encoding/base64"
 	"io"
 	"net/http"
 	"net/http/httptest"
@@ -26,6 +27,7 @@ import (
 	"connectrpc.com/connect"
 	"gitea.dev/actionslib/pkg/model"
 	runnerv1 "gitea.dev/actionslib/runner/v1"
+	log "github.com/sirupsen/logrus"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/mock"
 	"github.com/stretchr/testify/require"
@@ -403,3 +405,15 @@ func TestRestoreCalledWorkflowContext(t *testing.T) {
 		assert.Equal(t, "workflow_call", task.Context.AsMap()["event_name"])
 	})
 }
+
+func TestTaskLogFields(t *testing.T) {
+	fields := func(token string) log.Fields {
+		taskContext, err := structpb.NewStruct(map[string]any{"repository": "owner/repo", "run_id": "159", "run_number": "14", "gitea_runtime_token": token})
+		require.NoError(t, err)
+		return taskLogFields(&runnerv1.Task{Id: 72, Context: taskContext}, "build")
+	}
+	want := log.Fields{"task_id": int64(72), "job": "build", "repository": "owner/repo", "run_id": "159", "run_number": "14"}
+	assert.Equal(t, want, fields("malformed"))
+	want["job_id"] = int64(221)
+	assert.Equal(t, want, fields("header."+base64.RawURLEncoding.EncodeToString([]byte(`{"TaskID":72,"JobID":221}`))+".signature"))
+}