feat(telemetry): initial implementation — OpenTelemetry traces, metrics, logs (v1.0.0)

Introduces code.nochebuena.dev/einherjar/telemetry — the observability bootstrap
starter for the Einherjar framework. Absorbs the telemetry package from micro-lib,
migrating from OpenCensus to OpenTelemetry SDK v1.42.

Bootstrap functions (not lifecycle.Component — telemetry must be initialized before
the launcher starts, and its shutdown must run after all components stop):
- New(ctx, cfg) (func(context.Context) error, error) — production mode; exports
  traces, metrics, and logs via OTLP over gRPC to the configured endpoint;
  returns a shutdown function to be deferred in main()
- NewConsole(ctx, logger, cfg) (func(context.Context) error, error) — development
  mode; writes structured telemetry to the provided logging.Logger; no network
  dependency; suitable for local development and CI

Config (EINHERJAR_OTEL_* env vars):
  ServiceName(required), ServiceVersion(unknown), Environment(development),
  OTLPEndpoint(required for New), OTLPInsecure(false)

ConsoleConfig (EINHERJAR_OTEL_* env vars):
  ServiceName(required), ServiceVersion(unknown), Environment(development)

- identifiable.go: package-level Module variable (observability.Identifiable) for version
  identification — telemetry bootstraps before the launcher; not registered as a lifecycle component

identifiable.go

@@ -0,0 +1,32 @@
+package telemetry
+
+import (
+	"runtime/debug"
+
+	"code.nochebuena.dev/einherjar/contracts/observability"
+)
+
+// Module identifies this package to observability systems.
+// telemetry bootstraps before the launcher and is not registered as a lifecycle
+// component. Register Module manually with any version registry if needed.
+var Module observability.Identifiable = &moduleID{}
+
+type moduleID struct{}
+
+const modulePath = "code.nochebuena.dev/einherjar/telemetry"
+
+func (m *moduleID) ModulePath() string { return modulePath }
+
+func (m *moduleID) ModuleVersion() string {
+	if info, ok := debug.ReadBuildInfo(); ok {
+		for _, dep := range info.Deps {
+			if dep.Path == modulePath {
+				return dep.Version
+			}
+		}
+		if info.Main.Path == modulePath {
+			return info.Main.Version
+		}
+	}
+	return "(devel)"
+}