Support advanced prompt voice agent configuration

[JianW (v1212)]

Summary

• Builds on the previously merged prompt voice agent support by adding advanced, editable prompt voice configuration in azure.yaml.
• Aligns the azd authoring shape with the current sample expectations and Vienna prompt voice implementation surface: structured inputs, audio input/output tuning, output modalities, tools, and avatar configuration.
• Keeps existing simple prompt voice projects working by layering advanced overrides on top of the current defaults for model, instructions, voice, store, and audio pipeline.

Scope and compatibility

• This PR is a public-preview follow-up for kind: prompt-voice; it does not change hosted/container agent deployment behavior.
• Existing prompt voice YAML remains valid. Minimal managed/BYOM agents can still use only modelType, model.id, instructions, voice, and store.
• Advanced fields are optional and map to the prompt voice service contract where supported. Missing audio fields keep azd defaults.
• Other agent paths were reviewed for isolation: hosted/container mapping, code/container deploy, provisioning config, and non-voice service round-tripping remain unchanged.

Field coverage and source of truth

• audio, outputModalities, structuredInputs, tools, avatar, and store follow the Vienna prompt voice contract/tests and current prompt voice samples.
• azd validates stable local constraints that Vienna also validates, including supported audio formats (audio/pcm, audio/pcmu, audio/pcma), speed range, server VAD threshold range, and required avatar/voice fields.
• Extensible service areas remain intentionally light: tool objects and avatar extension fields are passed through to prompt voice service validation so azd does not block future Vienna/Voice Live additions.
• structuredInputs.defaultValue uses the azure.yaml camelCase authoring style and is converted to the service wire field default_value during deployment.

Implementation

• Extends prompt voice authoring models and REST payload models for advanced voice config.
• Updates mapping so audio, structuredInputs, outputModalities, tools, and avatar flow from YAML to the create request.
• Adds validation for local constraints such as audio format, turn detection ranges, output speed, and blank modalities.
• Updates the extension JSON schema and README with the advanced azure.yaml shape, known values, and pass-through boundaries.

Validation

• go test ./... -count=1
• go build ./...
• cspell lint 'extensions/**/*.go' 'extensions/**/*.md' --config ./.vscode/cspell.yaml --no-progress
• Live managed prompt voice deploy in France Central with advanced YAML: structured inputs, server VAD, transcription, Azure voice style, system tool, avatar, store; control-plane GET assertions passed.
• Live BYOM realtime prompt voice deploy in France Central with advanced YAML: self-deployed realtime model, semantic VAD, PCMU input, audio+text output modalities, function tool, structured inputs; control-plane GET assertions passed.
• Negative live smoke: audio/opus is rejected locally before deploy with a supported-format validation error.

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[microsoft-github-policy-service]

Hi @JianW (@v1212). Thank you for your interest in helping to improve the Azure Developer CLI experience and for your contribution. We've noticed that there hasn't been recent engagement on this pull request. If this is still an active work stream, please let us know by pushing some changes or leaving a comment. Otherwise, we'll close this out in 7 days.