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/

.devcontainer/devcontainer.json

@@ -0,0 +1,26 @@
+{
+	"name": "Go",
+	"image": "mcr.microsoft.com/devcontainers/go:2-1.25-trixie",
+	"features": {
+		"ghcr.io/devcontainers-extra/features/claude-code:1": {}
+	},
+	"forwardPorts": [],
+	"postCreateCommand": "go version",
+	"customizations": {
+		"vscode": {
+			"settings": {
+				"files.autoSave": "afterDelay",
+                "files.autoSaveDelay": 1000,
+                "explorer.compactFolders": false,
+                "explorer.showEmptyFolders": true
+			},
+			"extensions": [
+				"golang.go",
+				"eamodio.golang-postfix-completion",
+				"quicktype.quicktype",
+				"usernamehw.errorlens"
+			]
+		}
+	},
+	"remoteUser": "vscode"
+}