Add syntax highlighting to json + godot array save values

[tudddorrr]

JSON values render as JSON

• Save values holding a JSON document now pretty-print and colour-code inside the node, instead of collapsing into one flat value: {...} row. Highlighting is one regex pass, no new dependency.
• Covers values stored as strings, encoded twice ("{\"coins\":383131}"), and Godot var_to_str containers like Array[String]([...]).
• Anything that is not a document (1.50, true, null, "zip") still prints exactly as stored, so no row disappears.

Nodes size themselves

• Node width now comes from the browser, not from writing the measured size back onto the node: that rounded the width down and wrapped or clipped long JSON values.
• Long lines wrap under their own indentation rather than at the margin.

Copy button

• Only a row that holds a value (value: …) offers copy, so an array label like value [3] no longer does.