fix(apm): Enhance Synthetic Span Service Representation

[zarirhamza]

What does this PR do?

Rollout of span naming changes to align serverless product with tracer to create streamlined Service Representation for Serverless

Key Changes:

• Change service name to match instance name for all managed services (aws.lambda -> lambda name, etc) (breaking)

• Opt out via DD_TRACE_AWS_SERVICE_REPRESENTATION_ENABLED

• Add span.kind:server on synthetic spans made via span-inferrer, cold start and lambda invocation spans

• Remove _dd.base_service tags on synthetic spans to avoid unintentional service override

Motivation

Improve Service Map for Serverless. This allows for synthetic spans to have their own service on the map which connects with the inferred spans from the tracer side.

[joeyzhao2018]

LGTM

[Copilot]

Pull Request Overview

This PR enhances synthetic span service representation to improve Serverless Service Map functionality by aligning with tracer behavior. It implements a configurable service naming strategy that defaults to using instance-specific names instead of generic AWS service names, while maintaining backwards compatibility through an environment variable.

Key Changes:

• Modify service naming to use instance names (e.g., lambda function name, S3 bucket name) as service names instead of generic AWS service names
• Add environment variable DD_TRACE_AWS_SERVICE_REPRESENTATION_ENABLED to control this behavior (opt-out when set to "false")
• Add span.kind:server tag to synthetic spans and remove _dd.base_service tags to prevent unintentional service overrides

Reviewed Changes

Copilot reviewed 18 out of 18 changed files in this pull request and generated 4 comments.

Show a summary per file

File	Description
bottlecap/src/lifecycle/invocation/triggers/mod.rs	Add service name resolution logic with environment variable support and instance name fallback
bottlecap/src/lifecycle/invocation/processor.rs	Update main processor to use new service naming strategy and add span.kind tag
bottlecap/src/lifecycle/invocation/span_inferrer.rs	Add span.kind:server tag to inferred spans
bottlecap/src/traces/trace_processor.rs	Remove _dd.base_service tag from spans to prevent service override
bottlecap/tests/service_naming_test.rs	Add comprehensive tests for new service naming behavior
Various trigger event files	Update all trigger implementations to use new service resolution signature
bottlecap/tests/payloads/eventbridge_span.json	Update test payload to reflect new service naming

[duncanista]

LGTM – just left a comment!