SDK User-Agent prefixes feel confusing / outdated

[deyaaeldeen]

Some service teams (AI Projects in particular) are getting confused by our JS SDK UA strings, e.g.:

`azsdk-js-client azsdk-js-api azsdk-js-ai-projects/2.0.0-beta.4 core-rest-pipeline/1.22.2 Node/22.14.0 (...)`

The main questions coming up:

• What do azsdk-js-client vs azsdk-js-api actually represent today?
• Do those distinctions still make sense for newer SDKs that don’t really expose a REST/API layer anymore?
• Are these prefixes still intentionally meaningful, or mostly legacy from older layering assumptions?

Totally understand that UA changes are risky (telemetry, pipelines, regexes, etc.), so this isn’t proposing a change outright. It just feels like:

• The current UA is hard to interpret for downstream teams
• The intent isn’t obvious without historical context
• Docs may not be doing enough to explain what’s going on

Curious what others think:

• Is this distinction still something we actively rely on?
• Do other languages do something similar?
• Would better docs alone be “good enough” here?

[deyaaeldeen]

Related: #2616

[dargilco]

The ask is to produce just this part: azsdk-js-ai-projects/2.0.0-beta.4 core-rest-pipeline/1.22.2 Node/22.14.0 (...), according to https://azure.github.io/azure-sdk/general_azurecore.html#telemetry-policy

[qiaozha]

@timovv Could you help take a look at this? I remember you previously had a discussion around it.