create colour scheme tructure

lua/paper-tonic-modern/groups/lsp.lua

@@ -0,0 +1,12 @@
+-- Paper Tonic Modern - LSP Highlight Groups
+-- LSP diagnostics and UI elements
+
+local colors = require('paper-tonic-modern.colors')
+
+return {
+  -- LSP groups (to be implemented in Phase 11.8)
+  DiagnosticError = { fg = colors.alert_strong },
+  DiagnosticWarn = { fg = colors.alert },
+  DiagnosticInfo = { fg = colors.question },
+  DiagnosticHint = { fg = colors.fg },
+}