api differences are resolved.

[guvenenb]

This PR contains changes required according to b/502462579. The added specs are as follows :

Root-Level Properties

url: Added as an output-only String field to expose the endpoint URL of the deployed reasoning engine.
trafficConfig: Added as a NestedObject to support traffic distribution. It includes trafficSplitManual for explicitly defining the percentage of traffic routed to specific runtime revisions (runtimeRevisionName and percent), and trafficSplitAlwaysLatest for routing 100% of traffic to the newest revision.

Updates in spec.deploymentSpec

agentServerMode: Added as an Enum to allow users to specify the feature mode of the agent server (as STABLE or EXPERIMENTAL).
agentGatewayConfig: Added as a NestedObject to configure governed access paths for both inbound traffic (clientToAgentConfig) and outbound traffic (agentToAnywhereConfig) using Google-managed Agent Gateways.
keepAliveProbe: Added as a NestedObject to define HTTP GET configurations (path and port) and maxSeconds to keep the container instance active.

Updates in spec (the agent capabilities)

agentCard: Added as a String (with JSON validation and custom flattener) to support the A2A Agent Card specification.
exampleStore: Added as a String to accept the resource reference link of the Example Store used to guide agent performance.

Updates to contextSpec

exampleStoreConfig: Added as a NestedObject inside the context specification. It includes similaritySearchConfig to define the target embeddingModel

[github-actions]

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