feat(adk): retain MCP server identities in runtime diagnostics

[Whxuan0701]

Summary

• preserve stable MCP server names in the Go runtime configuration for RemoteMCPServers and Agent Plugin MCP servers
• include the server name in structured MCP initialization, success, and failure logs
• identify plugin-provided servers as <plugin>/<server> so operators can distinguish multiple servers without relying on URLs or array indexes

This adds an optional runtime-only JSON field and does not change the public CRD schema. Configurations that omit name retain their existing behavior.

Testing

• cd go && go test ./api/adk ./adk/pkg/mcp ./core/v2/agentplugins ./core/v2/translator ./core/internal/controller/translator/agent
• cd go && go vet ./api/adk ./adk/pkg/mcp ./core/v2/agentplugins ./core/v2/translator ./core/internal/controller/translator/agent
• git diff --check

Risk / Notes

• name uses omitempty, so existing serialized runtime configs remain compatible.
• RemoteMCPServer names come from object metadata; Agent Plugin MCP names combine the validated plugin manifest name with the server key.
• MCP transport construction and tool filtering are unchanged.