Add OpenTelemetry tracing for websocket flows

[marcodejongh]

No description provided.

[claude]

Claude Review

⚠️ Needs attention - Missing dependency declaration will break build; code duplication could be refactored.

Critical

• Missing dependency: packages/shared-schema/src/trace.ts imports from @opentelemetry/api but this dependency is not added to packages/shared-schema/package.json. Build will fail.

Issues

• Duplicated runWithSpan and attachTrace helpers: Identical implementations in packages/backend/src/graphql/resolvers/queue/mutations.ts and packages/backend/src/graphql/resolvers/sessions/mutations.ts. Extract to shared module.
• Duplicated pickTraceCarrier function: Near-identical implementations in packages/backend/src/websocket/setup.ts and packages/web/app/components/graphql-queue/graphql-client.ts. Consider adding to @boardsesh/shared-schema since TraceCarrier type is already there.
• Hardcoded localhost fallback in packages/web/app/otel/init-otel.ts:25: Falls back to http://localhost:4318/v1/traces which will silently fail in production. Consider disabling tracing entirely when no endpoint is configured rather than sending to unreachable localhost.

Missing Tests

• No tests for trace context propagation utilities (injectTraceContext, extractTraceContext, mergeExtensions)
• No tests for runWithSpan error handling and span lifecycle

Documentation

• New docs/observability.md appropriately documents the tracing setup.

[chatgpt-codex-connector]

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[chatgpt-codex-connector]

Initialize tracing before loading instrumented modules

setupTracing() is invoked inside main(), but all static imports run first; that means ./redis/client (which imports ioredis at module load) is loaded before registerInstrumentations({ instrumentations: [new IORedisInstrumentation()] }) runs in observability/tracing.ts. In this ordering, the ioredis patch is applied too late, so Redis spans are never emitted even though tracing is enabled.

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[chatgpt-codex-connector]

Propagate trace context through GraphQL response extensions

attachTrace stores the carrier on a private __trace property of the event object, but subscription responses are serialized from schema-selected fields, so this property is not delivered to clients; the web client then looks for traceparent/tracestate/baggage in payload extensions/data and finds nothing. As a result, graphql.ws.message spans cannot inherit mutation/session context, breaking the intended end-to-end websocket trace linkage.

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[chatgpt-codex-connector]

Declare @opentelemetry/api in shared-schema dependencies

This new module imports @opentelemetry/api, but packages/shared-schema/package.json was not updated to declare that dependency. Relying on other workspaces to hoist it creates an undeclared transitive dependency and can fail in isolated workspace installs or stricter package manager layouts.

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