feat(errortracking): extend agenttelemetry component with error log submission

- Add SubmitErrorLog(ErrorLog) to the component interface
- Add bounded errLogsCh channel, non-blocking SubmitErrorLog(), and flushErrortracking() scheduler job
- Add errortracking_sender.go: converts ErrorLog to dd-go Log with stack symbolization
- Add logs_payload.go: builds LogsPayload batches for HTTP POST
- Refactor sender.go: extract shared sendPayloadBody() helper reused by metrics and logs paths

Author: pducolin

comp/core/agenttelemetry/def/BUILD.bazel

@@ -5,5 +5,8 @@ go_library(
     srcs = ["component.go"],
     importpath = "github.com/DataDog/datadog-agent/comp/core/agenttelemetry/def",
     visibility = ["//visibility:public"],
-    deps = ["//pkg/fleet/installer/telemetry"],
+    deps = [
+        "//pkg/fleet/installer/telemetry",
+        "//pkg/util/log/errortracking",
+    ],
 )

comp/core/agenttelemetry/def/component.go

@@ -10,6 +10,7 @@ import (
 	"context"
 
 	installertelemetry "github.com/DataDog/datadog-agent/pkg/fleet/installer/telemetry"
+	"github.com/DataDog/datadog-agent/pkg/util/log/errortracking"
 )
 
 // team: agent-runtimes
@@ -21,5 +22,26 @@ type Component interface {
 	//    payload     - de-serializable into JSON
 	SendEvent(eventType string, eventPayload []byte) error
 
+	// SubmitErrorLog accepts a single error log record from the
+	// pkg/util/log slog handler and enqueues it for asynchronous flush
+	// to the internal agent telemetry intake. Implementations
+	// MUST be non-blocking on the hot path: enqueue to a bounded buffer
+	// and drop silently on overflow.
+	//
+	// Recursion prevention: the flush path
+	// (sendLogsBatch → sendPayload) MUST NOT log at
+	// Error or above. A flush-path Errorf would re-enter the slog
+	// handler and feed records back into this same channel. This
+	// invariant is enforced by convention — there is no runtime
+	// caller-identity guard. See
+	// comp/core/agenttelemetry/impl/errortracking_sender.go. If a
+	// flush fails, the failed batch is not re-attempted; the Debug-level
+	// log is the only signal.
+	//
+	// This method receives the ErrorLog value-type defined at
+	// pkg/util/log/errortracking; the component never sees raw slog
+	// types on its public surface.
+	SubmitErrorLog(log errortracking.ErrorLog)
+
 	StartStartupSpan(operationName string) (*installertelemetry.Span, context.Context)
 }

comp/core/agenttelemetry/def/go.mod

@@ -2,11 +2,13 @@ module github.com/DataDog/datadog-agent/comp/core/agenttelemetry/def
 
 go 1.25.0
 
-require github.com/DataDog/datadog-agent/pkg/fleet/installer v0.70.0
+require (
+	github.com/DataDog/datadog-agent/pkg/fleet/installer v0.70.0
+	github.com/DataDog/datadog-agent/pkg/util/log v0.73.2
+)
 
 require (
 	github.com/DataDog/datadog-agent/pkg/template v0.73.2 // indirect
-	github.com/DataDog/datadog-agent/pkg/util/log v0.73.2 // indirect
 	github.com/DataDog/datadog-agent/pkg/util/scrubber v0.73.2 // indirect
 	github.com/DataDog/datadog-agent/pkg/version v0.73.2 // indirect
 	github.com/ebitengine/purego v0.10.0 // indirect

comp/core/agenttelemetry/fx/go.mod

@@ -47,6 +47,7 @@ require (
 	github.com/DataDog/datadog-agent/pkg/util/hostinfo v0.0.0-20251027120702-0e91eee9852f // indirect
 	github.com/DataDog/datadog-agent/pkg/util/http v0.75.4 // indirect
 	github.com/DataDog/datadog-agent/pkg/util/log v0.75.4 // indirect
+	github.com/DataDog/datadog-agent/pkg/util/log/setup v0.0.0-00010101000000-000000000000 // indirect
 	github.com/DataDog/datadog-agent/pkg/util/option v0.75.4 // indirect
 	github.com/DataDog/datadog-agent/pkg/util/pointer v0.75.4 // indirect
 	github.com/DataDog/datadog-agent/pkg/util/scrubber v0.75.4 // indirect

comp/core/agenttelemetry/impl/BUILD.bazel

@@ -5,6 +5,8 @@ go_library(
     srcs = [
         "agenttelemetry.go",
         "config.go",
+        "errortracking_sender.go",
+        "logs_payload.go",
         "runner.go",
         "sender.go",
         "utils.go",
@@ -24,32 +26,41 @@ go_library(
         "//pkg/fleet/installer/telemetry",
         "//pkg/util/hostinfo",
         "//pkg/util/http",
+        "//pkg/util/log/errortracking",
+        "//pkg/util/log/setup",
         "//pkg/util/scrubber",
         "//pkg/version",
         "@com_github_datadog_zstd//:zstd",
         "@com_github_prometheus_client_model//go",
         "@com_github_robfig_cron_v3//:cron",
         "@in_yaml_go_yaml_v2//:yaml",
+        "@org_uber_go_atomic//:atomic",
     ],
 )
 
 go_test(
     name = "impl_test",
-    srcs = ["agenttelemetry_test.go"],
+    srcs = [
+        "agenttelemetry_test.go",
+        "errortracking_sender_test.go",
+    ],
     embed = [":impl"],
     gotags = ["test"],
     deps = [
         "//comp/core/log/def",
         "//comp/core/log/mock",
         "//comp/core/telemetry/def",
         "//comp/core/telemetry/mock",
+        "//comp/logs/agent/config",
         "//pkg/config/mock",
         "//pkg/util/fxutil",
         "//pkg/util/jsonquery",
+        "//pkg/util/log/errortracking",
         "@com_github_datadog_zstd//:zstd",
         "@com_github_prometheus_client_model//go",
         "@com_github_stretchr_testify//assert",
         "@com_github_stretchr_testify//mock",
         "@com_github_stretchr_testify//require",
+        "@org_uber_go_atomic//:atomic",
     ],
 )