feat: align RLE manifests and harness scaffolds

[Sujit Kamireddy (sujit-kamireddy)]

Summary

• replace local .azd-rle.json state with the host-agnostic rle.toml release contract
• make (rle.name, rle.version) the immutable RLE identity and derive the explicit service version bump at publish time
• use canonical control-plane pairs: Gym: OpenEnv, Harness: HostedAgent, and Harness: BYOH
• render user-facing type/subtype pairs with a colon while retaining separate structured type and subtype fields
• keep Foundry project and ACR endpoints in runtime environment variables, not source configuration
• keep model configuration as a rollout-time input rather than registered RLE identity
• pin local and source-free remote invocation to an explicit release version
• add feature-gated Foundry Hosted Agent-backed and BYOH OpenEnv harness scaffolds
• reject retired Agent, BYOA, and AZD_AI_RLE_AGENT_INIT_ENABLE inputs with no compatibility aliases

Contract naming

• BYOH is the compact wire abbreviation for Bring Your Own Harness.
• HostedAgent is the host-agnostic subtype for a Foundry Hosted Agent backing the harness; the platform name remains documentation rather than manifest syntax.

Control-plane contract

• Synchronized with Vienna PR #2298659, which makes the same clean breaking preview-contract rename at the API boundary.

Companion samples PR

• feat: add canonical RLE sample manifests sujit-kamireddy/rle-samples#2 must merge before this CLI change is released, so the catalog's Gym: OpenEnv samples contain canonical manifests.

Validation

• go test ./... from cli/azd/extensions/azure.ai.rle
• AZD_TEST_RLE_DOCKER_E2E=1 go test ./internal/project -run "^TestCreateRleHarnessScaffoldRunsOpenEnvRuntime$" -count=1 -v
• rebuilt and installed the extension with azd x build, then exercised Harness: HostedAgent, Harness: BYOH, retired-value rejection, and local OpenEnv execution through azd ai rle

[azure-pipelines]

Azure Pipelines:
There may be pipelines that require an authorized user to comment /azp run to run.