Tag the deploy step span with the service host kind for per-service deploy telemetry

[therealjohn]

Summary

The deploy step span emitted by the up/deploy execution graph does not carry the service host kind, so telemetry cannot reliably attribute a specific deploy step to its host (e.g. azure.ai.agent) in multi-service projects. Adding the host to the deploy step's tags (one line) makes per-host deploy success/failure metrics queryable across single- and multi-service projects.

Background

For each service, the up/deploy graph creates a deploy step:

// cli/azd/internal/cmd/service_graph.go (~line 517)
deployStepName := "deploy-" + svc.Name
...
g.AddStep(&exegraph.Step{
    Name: deployStepName,        // "deploy-<svcName>"  (service name, not host)
    Tags: []string{"deploy"},    // no host kind
    ...
})

The scheduler emits an exegraph.step span per step with exegraph.step.name, exegraph.step.tags, and per-step Success/ResultCode (cli/azd/pkg/exegraph/scheduler.go).

Neither serviceManager.Deploy (cli/azd/pkg/project/service_manager.go) nor the extension bridge ExternalServiceTarget.Deploy (cli/azd/pkg/project/service_target_external.go) starts a span or sets a host attribute, and the root command span's project.service.hosts / project.service.targets are independently sorted sets with no service-name -> host mapping (cli/azd/pkg/project/project.go, cli/azd/pkg/project/project_manager.go).

Impact

Today telemetry/dashboards can determine that a project contains an azure.ai.agent service and that a deploy-* step succeeded or failed, but cannot tie a specific deploy step to its host kind. Per-host deploy reliability metrics (for example, the Foundry hosted-agent deploy-step reliability metric in the agents telemetry data contract) are therefore only clean for single-service projects; multi-service projects conflate the agent's deploy step with other services' deploy steps.

Proposed fix (one line)

Include the host kind in the deploy step tags:

// cli/azd/internal/cmd/service_graph.go
Tags: []string{"deploy", string(svc.Host)},

This makes exegraph.step.tags equal to e.g. ["deploy","azure.ai.agent"], so a query like
Properties['exegraph.step.tags'] has "azure.ai.agent" identifies the agent's deploy step directly, in single- and multi-service projects.

Alternative: add a dedicated singular project.service.host attribute on the deploy step span for cleaner grouping (instead of overloading tags).

Notes

• Host kinds are low-cardinality and non-PII (e.g. containerapp, appservice, azure.ai.agent), so they are safe to emit as telemetry.
• Consider doing the same for the package-<svc> / publish-<svc> steps for symmetry.
• The new tag value / attribute may need classification in the Data Catalog portal before it appears in dashboards.