feat(pivot): port kernelevents off internal pipeline+consumer to upstream

[trilamsr]

Summary

Ports components/receivers/kernelevents/ off the soon-to-be-deleted internal/{pipeline,consumer,runtime/lifecycle} packages onto upstream OTel collector v1.59.0 / v0.153.0. Mirrors PR-B2 (#201) for the multi-source kernelevents shape — receiver-scoped lifecycle helper keeps its Add() method (one goroutine per source under one WaitGroup); only the logger type flips from *slog.Logger to *zap.Logger. Net delta: +317 / -296 LOC across 28 files in components/receivers/kernelevents/ plus go.mod (promotes componenttest, pipeline from indirect to direct).

Root cause

RFC-0013 PR-F deletes internal/pipeline, internal/consumer, and internal/runtime/lifecycle. Every receiver must consume upstream types directly. PR #187 already pulled the receiver-local lifecycle + selftel siblings into this package (preempting the internal-lifecycle dep) but kept *slog.Logger and the internal/pipeline factory shape. This PR completes the swap.

Type-swap applied

internal	upstream
internal/pipeline.Type	component.Type
internal/pipeline.ReceiverFactory	receiver.Factory (via receiver.NewFactory(...))
internal/pipeline.CreateSettings	receiver.Settings (via receivertest.NewNopSettings)
internal/pipeline.Config	component.Config
internal/pipeline.Receiver	receiver.Logs (compile-time var _ receiver.Logs = (*kernelEventsReceiver)(nil))
internal/pipeline.Host	component.Host (via componenttest.NewNopHost)
internal/pipeline.ComponentState mixin	dropped (Started()/Stopped() accessors were unused)
internal/pipeline.ErrSignalNotSupported	pipeline.ErrSignalNotSupported (auto-surfaced by receiver.NewFactory default)
internal/pipeline/pipelinetest.New(t)	local testSettings(t) wrapper + componenttest.NewNopHost
internal/consumer.{Logs,Capabilities,Metrics,Traces}	upstream consumer.*
internal/pipeline.TelemetrySettings.{Logger,MeterProvider,Resource}	receiver.Settings.{Logger,MeterProvider,Resource} (TelemetrySettings embedded, no .Telemetry indirection)
*slog.Logger everywhere (lifecycle, source, kmsg, journald, factory, kernelevents.go, all tests)	*zap.Logger
slog.Default()	zap.NewNop()

Behavior changes (deliberate)

• Shutdown surfaces lifecycle ctx-deadline error: previously _ = r.lc.Shutdown(ctx) silently swallowed any deadline-exceeded; now wrapped + returned (kernelevents lifecycle shutdown: %w). Matches PR-B2 nccl_fr discipline. TestReceiver_ShutdownIsIdempotent still passes (second Shutdown short-circuits to the first call's stashed error, which is nil on success).
• Factory shape: package-var Factory removed; NewFactory() returns a fresh receiver.Factory per call (matches upstream-contrib pattern + PR-B2 nccl_fr). Stability pinned at component.StabilityLevelBeta.
• No ComponentState mixin: Started() / Stopped() accessors had no callers; dropping the embed removes the only stateful field the receiver carried for upstream interface satisfaction.

Behavior preserved

• Multi-source Add() lifecycle contract — TOCTOU-safe under the closed mutex guard; TestKernelevents_Lifecycle_ConcurrentAddDuringShutdown_NoPanic passes under -race (the only mode it exercises; flaky without -race as documented in the test docstring).
• Per-source isolation (each source owns its OWN *lifecycle; receiver hosts the driver goroutine).
• Sibling-isolation invariant + cancel cascade (Start-ctx cancellation reaches every source without an explicit Shutdown).
• Self-telemetry: metric names + label shape unchanged (tracecore.receiver.errors_total{kind,component_id} and siblings); instrumentation scope = receiver's Go import path.
• Schema URL (kernelEventsSchemaURL), attribute set, severity mapping, partial-source mode, regex / facility / min-severity filters, kmsg bufio.ErrTooLong → kindKmsgOversized discrimination, journald restart-with-backoff + slow-recovery loop.

Test plan

• make check — 0 issues.
• go test -race ./components/receivers/kernelevents/... — pass.
• go test ./... — pass for kernelevents; two unrelated pre-existing race-window flakes (TestK8sevents_Lifecycle_ConcurrentAddDuringShutdown_NoPanic, TestServer_HealthzReturns503DuringShutdown) both pass under -race.
• Concurrent-Add stress test passes under -race (first try; the test is -race-only by design).
• Compile-time assertion var _ receiver.Logs = (*kernelEventsReceiver)(nil) guards against upstream interface drift.
• go.mod tidies cleanly with componenttest + pipeline promoted indirect → direct.

Out of scope

• internal/sli import in bench_test.go (SLI summary publisher, not deleted by PR-F).
• internal/pipeline/pipelinetest deletion (covered by sibling PRs).
• Source-template .go.example parser-gate test — comment refreshed; the template's package-kernelevents private-type usage means the parse-only gate is unchanged.

NONE