chore: baseline snapshot before moderation-strictness feature

Repo .git was damaged (refs/ missing, index truncated, object store near-empty).
Repaired via git init (rebuilt refs), stale index preserved as .git/index.corrupt-20260910.bak,
then full worktree committed as a rollback baseline.

internal/tracing/config.go

@@ -0,0 +1,62 @@
+// Copyright 2022 E99p1ant. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package tracing
+
+import (
+	"go.opentelemetry.io/otel"
+	"go.opentelemetry.io/otel/propagation"
+	"go.opentelemetry.io/otel/trace"
+)
+
+// config is a group of options for this instrumentation.
+type config struct {
+	TracerProvider trace.TracerProvider
+	Propagators    propagation.TextMapPropagator
+}
+
+// Option applies an option value for a config.
+type Option interface {
+	apply(*config)
+}
+
+// newConfig returns a config configured with all the passed Options.
+func newConfig(opts []Option) *config {
+	c := &config{
+		Propagators:    otel.GetTextMapPropagator(),
+		TracerProvider: otel.GetTracerProvider(),
+	}
+	for _, o := range opts {
+		o.apply(c)
+	}
+	return c
+}
+
+type propagatorsOption struct{ p propagation.TextMapPropagator }
+
+func (o propagatorsOption) apply(c *config) {
+	if o.p != nil {
+		c.Propagators = o.p
+	}
+}
+
+// WithPropagators returns an Option to use the Propagators when extracting
+// and injecting trace context from HTTP requests.
+func WithPropagators(p propagation.TextMapPropagator) Option {
+	return propagatorsOption{p: p}
+}
+
+type tracerProviderOption struct{ tp trace.TracerProvider }
+
+func (o tracerProviderOption) apply(c *config) {
+	if o.tp != nil {
+		c.TracerProvider = o.tp
+	}
+}
+
+// WithTracerProvider returns an Option to use the TracerProvider when
+// creating a Tracer.
+func WithTracerProvider(tp trace.TracerProvider) Option {
+	return tracerProviderOption{tp: tp}
+}