feat(telemetry): initial stable release v0.9.0

Single-call OTel SDK bootstrap setting all three global providers (traces → Tempo, metrics → Mimir, logs → Loki) over OTLP gRPC.

What's included:
- New(ctx, Config): bootstraps TracerProvider, MeterProvider, and LoggerProvider with OTLP gRPC exporters; sets OTel globals
- W3C TraceContext + Baggage propagation set globally
- Resource tagging: service.name, service.version, deployment.environment merged with SDK defaults
- OTLPInsecure bool for development environments without TLS
- Sequential rollback on partial initialization failure — no dangling exporters on error
- Returns shutdown func(context.Context) error; caller defers in main or wires into launcher BeforeStop
- Tier 5 module: must be imported only by application main packages; zero micro-lib dependencies

Tested-via: todo-api POC integration
Reviewed-against: docs/adr/

go.mod

@@ -0,0 +1,35 @@
+module code.nochebuena.dev/go/telemetry
+
+go 1.25.0
+
+require (
+	go.opentelemetry.io/otel v1.42.0
+	go.opentelemetry.io/otel/exporters/otlp/otlplog/otlploggrpc v0.18.0
+	go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetricgrpc v1.42.0
+	go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc v1.42.0
+	go.opentelemetry.io/otel/log v0.18.0
+	go.opentelemetry.io/otel/sdk v1.42.0
+	go.opentelemetry.io/otel/sdk/log v0.18.0
+	go.opentelemetry.io/otel/sdk/metric v1.42.0
+)
+
+require (
+	github.com/cenkalti/backoff/v5 v5.0.3 // indirect
+	github.com/cespare/xxhash/v2 v2.3.0 // indirect
+	github.com/go-logr/logr v1.4.3 // indirect
+	github.com/go-logr/stdr v1.2.2 // indirect
+	github.com/google/uuid v1.6.0 // indirect
+	github.com/grpc-ecosystem/grpc-gateway/v2 v2.28.0 // indirect
+	go.opentelemetry.io/auto/sdk v1.2.1 // indirect
+	go.opentelemetry.io/otel/exporters/otlp/otlptrace v1.42.0 // indirect
+	go.opentelemetry.io/otel/metric v1.42.0 // indirect
+	go.opentelemetry.io/otel/trace v1.42.0 // indirect
+	go.opentelemetry.io/proto/otlp v1.9.0 // indirect
+	golang.org/x/net v0.51.0 // indirect
+	golang.org/x/sys v0.41.0 // indirect
+	golang.org/x/text v0.34.0 // indirect
+	google.golang.org/genproto/googleapis/api v0.0.0-20260209200024-4cfbd4190f57 // indirect
+	google.golang.org/genproto/googleapis/rpc v0.0.0-20260209200024-4cfbd4190f57 // indirect
+	google.golang.org/grpc v1.79.2 // indirect
+	google.golang.org/protobuf v1.36.11 // indirect
+)