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

.gitignore

@@ -0,0 +1,38 @@
+# ── Release workflow helpers ──────────────────────────────────────────────────
+COMMIT.md
+PR.md
+RELEASE.md
+
+# ── Go build artifacts ────────────────────────────────────────────────────────
+*.exe
+*.exe~
+*.dll
+*.so
+*.dylib
+*.test
+*.out
+/dist/
+/bin/
+
+# ── Go workspace (local development only) ────────────────────────────────────
+go.work
+go.work.sum
+
+# ── Dependency vendor directory ───────────────────────────────────────────────
+vendor/
+
+# ── Coverage output ───────────────────────────────────────────────────────────
+coverage.out
+coverage.html
+*.coverprofile
+
+# ── OS artifacts ─────────────────────────────────────────────────────────────
+.DS_Store
+Thumbs.db
+
+# ── Editor artifacts ──────────────────────────────────────────────────────────
+.idea/
+.vscode/
+*.swp
+*.swo
+*~