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

README.md

@@ -0,0 +1,107 @@
+# einherjar/telemetry
+
+[![version](https://img.shields.io/badge/version-v1.0.0-5C4EE5?style=flat-square)](https://code.nochebuena.dev/einherjar/telemetry)
+[![license](https://img.shields.io/badge/license-AGPL--3.0-22863A?style=flat-square)](LICENSE)
+[![go](https://img.shields.io/badge/Go-1.26+-00ADD8?style=flat-square&logo=go&logoColor=white)](https://go.dev)
+
+> Huginn and Muninn fly each day over the world. They see everything. They report back.
+
+`code.nochebuena.dev/einherjar/telemetry` is the OpenTelemetry bootstrap component of the Einherjar framework. It initializes traces, metrics, and structured logs via OTLP over gRPC — vendor-neutral, compatible with Grafana, Jaeger, Tempo, Datadog, and Honeycomb. A console mode is available for local development without a collector.
+
+Telemetry is **not** a `lifecycle.Component`. It must be initialized before the launcher and shut down after all components stop — the returned shutdown function handles this cleanly with a `defer`.
+
+---
+
+## Usage
+
+### Production (OTLP/gRPC)
+
+```go
+import (
+    "code.nochebuena.dev/einherjar/telemetry"
+    "code.nochebuena.dev/einherjar/core/launcher"
+    "code.nochebuena.dev/einherjar/core/logz"
+)
+
+ctx := context.Background()
+logger := logz.New(logz.Config{JSON: true})
+
+// Initialize telemetry BEFORE the launcher.
+// Defer the shutdown BEFORE launcher.Run() so it fires after the launcher stops.
+shutdown, err := telemetry.New(ctx, telemetry.DefaultConfig())
+if err != nil {
+    logger.Error("telemetry init failed", err)
+    os.Exit(1)
+}
+defer shutdown(ctx)
+
+lc := launcher.New(logger)
+lc.Append(db, cache, srv)
+lc.Run()
+```
+
+### Development (console / structured log output)
+
+No collector required. Spans and metrics are emitted to the configured `logging.Logger`.
+
+```go
+shutdown, err := telemetry.NewConsole(ctx, logger, telemetry.DefaultConsoleConfig())
+if err != nil {
+    logger.Error("telemetry init failed", err)
+    os.Exit(1)
+}
+defer shutdown(ctx)
+```
+
+---
+
+## Environment variables
+
+### Production (`telemetry.New`)
+
+| Variable | Required | Default | Description |
+|---|---|---|---|
+| `EINHERJAR_OTEL_SERVICE_NAME` | Yes | — | Service name reported to the collector |
+| `EINHERJAR_OTEL_EXPORTER_ENDPOINT` | Yes | — | OTLP gRPC endpoint (e.g. `otel-collector:4317`) |
+| `EINHERJAR_OTEL_SERVICE_VERSION` | No | `unknown` | Service version tag |
+| `EINHERJAR_OTEL_ENVIRONMENT` | No | `development` | Deployment environment tag |
+| `EINHERJAR_OTEL_EXPORTER_INSECURE` | No | `false` | Disable TLS for the exporter (dev/local) |
+
+### Development (`telemetry.NewConsole`)
+
+| Variable | Required | Default | Description |
+|---|---|---|---|
+| `EINHERJAR_OTEL_SERVICE_NAME` | Yes | — | Service name |
+| `EINHERJAR_OTEL_SERVICE_VERSION` | No | `unknown` | Service version tag |
+| `EINHERJAR_OTEL_ENVIRONMENT` | No | `development` | Deployment environment tag |
+
+---
+
+## Dependency graph
+
+```
+contracts  (zero dependencies)
+    ↑
+  core
+    ↑
+telemetry  (contracts, core, otel SDK + OTLP exporters)
+    ↑
+  your app (initialized before launcher.Run)
+```
+
+---
+
+## Verification
+
+```bash
+cd telemetry/
+go build ./...
+go vet ./...
+go test ./...
+gofmt -l .
+```
+
+---
+
+> *Odin gave an eye for wisdom.*
+> *Observability is the eye that watches the living system.*