LSP Server for included_icons.txt

An optional Language Server Protocol implementation that provides diagnostics and syntax highlighting for included_icons.txt files in any LSP-capable editor. What it gives the editor:

• Diagnostics: parses included_icons.txt on open / change / save, flags syntax errors and bad size-matrix expressions with line + column ranges.
• Theme validation: built-in theme NAMES plus any # @extra-icon-theme NAME PATH directives in the file are accepted; anything else gets an "Unknown theme" error. The LSP does not read CLI flags, so themes added only via --extra-icon-theme won't be recognized -- declare them with the in-file directive (see README).
• Directive path check: a directive whose PATH doesn't resolve gets a Warning (not Error), so editing in-flight doesn't go red.
• Semantic tokens: colors theme name, context, icon name, size matrix pieces (input number / output number / operator / scalable keyword), comments, and the # @extra-icon-theme directive parts (decorator-style keyword + NAME + PATH). Needs an LSP client that supports textDocument/semanticTokens/full (Eglot >= 1.20; Neovim, Helix).
• Hover: mouse-over (or M-x eldoc-print-current-symbol-info / K in Neovim) shows what each token means -- theme name, context, icon name, size matrix pieces, directive parts, etc.