fix: syntax colors and colorized brackets

[alihakankurt]

Summary

• Fix some syntax token colors to match the Rosé Pine palette specification
• Introduce new syntax tokens for LSP semantic highlights
• Add accents array to use colorized brackets with Rosé Pine colors
• Use $highlightHigh for border.variant to visually separate elevated surfaces (e.g. command palette, context menu)

Details

• Palette fixes: constant/number → $rose, enum → $foam, preproc → $pine, property → $iris, string.escape/string.special → $iris, string.special.symbol → $gold.
• Semantic tokens added:
  • Constants: constant.builtin, constant.macro
  • Functions: function.builtin, function.call, function.decorator, function.macro, function.method, function.method.call
  • Keywords: keyword.modifier, keyword.preproc
  • Modules: module, namespace
  • Tags: tag.doctype, tag.attribute, tag.delimiter
  • Types: type.builtin, type.class, type.enum, type.interface, type.struct, type.parameter, type.definition, …
  • Variables: variable.builtin, variable.parameter
  • Text: text
• Bracket colorization: added accents array ($love, $gold, $rose, $pine, $foam, $iris) so matching brackets are tinted with palette colors.
• Elevated surfaces: border.variant now uses $highlightHigh instead of $surface to delineate popovers/menus.

Notes

• I based these token choices on commonly used languages such as C/C++, C#, Rust, Python, XML/HTML, and JS/TS.
• With the property change, JSON keys now use $iris instead of $foam. If we'd prefer to keep $foam for JSON keys, we can add property.json_key to override it.

Screenshots

• Current

• Updated (with semantic_tokens set to combined)

Issues

Fixes #26
Fixes #30