[BUG] No syntax highlighting for GDScript (.gd) files

Found 3 possible duplicate issues:

1. https://github.com/anthropics/claude-code/issues/39805
2. https://github.com/anthropics/claude-code/issues/28192
3. https://github.com/anthropics/claude-code/issues/21834

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🤖 Generated with Claude Code

Not a duplicate.
Linked issues are about syntax highlighting being broken globally (all languages affected).
This issue is specifically about GDScript (.gd files) not having a grammar registered.
Other languages (TypeScript, Python, Rust, etc.) highlight correctly in the same session.

Still reproducible on 2.1.114
Confirmed regression, worked in earlier versions (see second screenshot above).

This is not a duplicate of #39805 / #28192 / #21834 those describe highlighting being broken globally across all languages.
Here only .gd files are affected, TS / Python / Rust render correctly in the same session (see first screenshot).

Likely root cause: no GDScript grammar registered in the TUI highlighter bundle. Official MIT-licensed TextMate grammar: https://github.com/godotengine/godot-vscode-plugin/blob/master/syntaxes/GDScript.tmLanguage.json

Cross-device reproduction + drop-in fix proposal

Not local - reproduced on multiple machines

Asked another developer to repro independently on a separate machine - different hardware, fresh Claude Code install, no shared config or settings. Same result: .gd diffs render as plain white while .ts / .py / .rs are colored correctly in the same session. Rules out my local environment, theme, terminal, or extension shadowing.

Highlighter stack

Confirmed via strings on the bundled binary: Claude Code TUI uses highlight.js for code/diff rendering. highlight.js ships ~190 grammars, but GDScript is not in the default set - that's the regression surface.

Drop-in fix (~10 lines)

Official community grammar exists and is maintained by the highlight.js org itself:

Repo: https://github.com/highlightjs/highlightjs-gdscript
License: BSD-3-Clause (compatible)
Author: maintained by highlightjs org + Calinou (Godot core contributor)

Integration matches the standard third-party grammar pattern:

import hljs from 'highlight.js';
import gdscript from './vendor/highlightjs-gdscript/dist/gdscript.min.js';

hljs.registerLanguage('gdscript', gdscript);

Plus an extension → language entry: '.gd' → 'gdscript' in whatever extension map the diff renderer uses.

That's the entire patch. No new dependency in package.json needed (single ~5KB JS file can be vendored), no behavior change for any other language, and .tres / .tscn files can map to the same grammar or ini as a separate follow-up.

Still reproducible on v2.1.170

Still reproducible on v2.1.202