JEP 401 Support value keyword

Vahalla is coming! But not too quick, it will be in preview in 28 (march 2027). So it’s time to support the new keyword `value`.

Small example
```java
public value record Vahalla(String value) {}
```

Actually with version `2.10.3` error is

> npx prettier --plugin=prettier-plugin-java --write "**/*.java"
src/main/java/wallet/Vahalla.java
[error] src/main/java/wallet/Vahalla.java: Error: Failed to parse: (program (package_declaration (identifier)) (method_declaration (modifiers (visibility)) type: (type_identifier) (ERROR (identifier)) name: (identifier) parameters: (formal_parameters (formal_parameter type: (type_identifier) name: (identifier))) body: (block)))

Reproduce the failure with the reported npx prettier --plugin=prettier-plugin-java --write command and the sample src/main/java/wallet/Vahalla.java input. Trace the Java parsing entry point that rejects the value declaration, then verify that the sample formats successfully without the parse error.

Written by the indexing model from the issue text.