fix(agents): resolve remote invoke name from inline service config

[glharper]

What

Remote azd ai agent invoke failed after initializing a unified azure.yaml against an existing (brownfield) Foundry project, even though the azure.ai.agent service and its agent name were declared inline.

The command failed with the misleading fallback error that an agent name was required.

Root cause

resolveAgentServiceFromProject populated AgentServiceInfo.AgentName only from the deployed environment output:

AGENT_<SERVICE>_NAME

That output is written after deployment. Brownfield init writes the hosted-agent definition — including its name — inline on the azure.ai.agent service, but does not create the deploy output. Therefore explicit-protocol remote invoke (--protocol invocations in the repro) resolved the service successfully but left the target agent name empty.

Using the azure.yaml service key as a fallback would be unsafe because the service key and deployed agent name may intentionally differ.

Fix

• Seed the resolved agent name from the inline/config-nested hosted-agent definition (project.AgentDefinitionFromService).
• Continue reading AGENT_<SERVICE>_NAME; when present, it overrides the inline definition because it reflects the resource actually deployed.
• Do not fall back to the service key.
• Keep malformed/missing inline definitions best-effort so existing deployed projects with environment outputs are not regressed.

This lets remote invoke work immediately for the reported brownfield/unified configuration while preserving deployed-name precedence after azd deploy.

Tests

• TestResolveAgentServiceFromProject_UsesInlineNameBeforeDeploy reproduces the issue: service key differs from the inline agent name and no AGENT_<SERVICE>_NAME exists. The inline name is resolved.
• TestResolveAgentServiceFromProject_EnvironmentNameWins verifies deployed environment output remains authoritative when it differs from the inline definition.

Validation

• go build ./...
• go test ./... -count=1 (all extension packages)
• go vet ./...
• gofmt clean
• golangci-lint run ./internal/cmd/... — 0 issues
• cspell — 0 issues

No CHANGELOG.md entry is included; extension changelog entries are added during the release process.

Fixes #9109

[github-actions]

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[Copilot]

Pull request overview

Fixes brownfield remote agent invocation by resolving the deployed agent name from inline service configuration.

Changes:

• Uses inline hosted-agent names before deployment outputs exist.
• Preserves environment output precedence.
• Adds regression tests for both resolution paths.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
internal/cmd/helpers.go	Adds inline agent-name fallback resolution.
internal/cmd/helpers_test.go	Tests fallback and deployed-name precedence.

[jongio]

Verified the fix locally. Seeding the agent name from the inline hosted-agent definition before reading AGENT_<SERVICE>_NAME correctly fixes brownfield pre-deploy remote invoke, and the environment output still wins once it exists since it's applied after. All callers already guard on a non-empty AgentName, so no downstream regression. Both regression tests pass here.