Refactor Paper Tonic Modern colorscheme and enhance semantic highlighting

- Updated highlights.scm to improve CSS, HTML, and data attribute captures with higher priority.
- Added a new Lua function to display highlight group and color information under the cursor.
- Expanded editor, semantic, syntax, and TreeSitter highlight groups for better visual consistency across languages.
- Created test files for PHP, HTML, CSS, and Lua to validate syntax highlighting.
- Implemented a shell script to test semantic highlights in a Neovim session.
- Simplified colorscheme loading process by removing unnecessary plugin specifications.

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

@@ -1,9 +1,132 @@
 -- Paper Tonic Modern - Editor Highlight Groups
 -- Base Vim/Neovim UI elements
 
-local colors = require('paper-tonic-modern.colors')
+local c = require('paper-tonic-modern.colors')
 
 return {
-  -- Core editor elements (to be implemented in Phase 11.4)
-  Normal = { fg = colors.fg, bg = colors.bg },
+  -- ============================================================================
+  -- Core Editor Elements
+  -- ============================================================================
+  
+  Normal = { fg = c.fg, bg = c.bg },
+  NormalFloat = { fg = c.fg, bg = c.NONE },
+  FloatBorder = { fg = c.fg_stronger, bg = c.NONE },
+  
+  -- ============================================================================
+  -- Cursor & Line Highlighting
+  -- ============================================================================
+  
+  Cursor = { reverse = true },
+  CursorIM = 'Cursor',
+  CursorLine = { bg = c.bg_hl },
+  CursorLineNr = { fg = c.fg_weak, bold = true },
+  CursorColumn = { bg = c.bg_hl },
+  
+  -- ============================================================================
+  -- Line Numbers & Columns
+  -- ============================================================================
+  
+  LineNr = { fg = c.fg_weak },
+  SignColumn = { fg = c.NONE, bg = c.NONE },
+  ColorColumn = { bg = c.bg_hl_weak },
+  
+  -- ============================================================================
+  -- Visual Selection & Search
+  -- ============================================================================
+  
+  Visual = { bg = c.bg_hl_special },
+  VisualNOS = { fg = c.fg_strong, bg = c.bg_hl_special, bold = true },
+  
+  Search = { bg = c.bg_hl_special },
+  IncSearch = { reverse = true },
+  MatchParen = { bg = c.bg_hl_special_alt_strong, bold = true, underline = true, sp = c.fg_stronger },
+  
+  -- ============================================================================
+  -- Status Line & Tab Line
+  -- ============================================================================
+  
+  StatusLine = { fg = c.fg, bg = c.bg_ui, italic = true },
+  StatusLineNC = { fg = c.fg_weaker, bg = c.bg_ui, italic = true },
+  StatusLineTerm = 'StatusLine',
+  StatusLineTermNC = 'StatusLineNC',
+  
+  TabLine = 'StatusLineNC',
+  TabLineFill = { fg = c.bg_ui, bg = c.bg_ui },
+  TabLineSel = 'StatusLine',
+  
+  -- ============================================================================
+  -- Window Separators & Misc UI
+  -- ============================================================================
+  
+  VertSplit = { fg = c.bg_hl_strong },
+  Title = { bold = true },
+  Directory = { fg = c.primary_weak, bold = true },
+  
+  -- ============================================================================
+  -- Popup Menu (Completion)
+  -- ============================================================================
+  
+  Pmenu = { fg = c.fg, bg = c.bg_ui },
+  PmenuSel = { fg = c.fg_strong, bg = c.bg_ui, bold = true },
+  PmenuSbar = 'Pmenu',
+  PmenuThumb = 'Pmenu',
+  WildMenu = { fg = c.fg_strong, bg = c.bg_ui, bold = true },
+  
+  -- ============================================================================
+  -- Folds
+  -- ============================================================================
+  
+  Folded = { fg = c.fg_strong, bold = true },
+  FoldColumn = { fg = c.fg_weak },
+  
+  -- ============================================================================
+  -- Diffs
+  -- ============================================================================
+  
+  DiffAdd = { bg = c.bg_success },
+  DiffChange = { bg = c.bg_modified },
+  DiffDelete = { bg = c.bg_fail },
+  DiffText = { fg = c.fg_stronger, bg = c.bg_success },
+  
+  -- ============================================================================
+  -- Spelling
+  -- ============================================================================
+  
+  SpellBad = { fg = c.alert_strong, bg = c.bg_error_weak },
+  SpellCap = { fg = c.alert, bg = c.bg_error_weak },
+  SpellLocal = { fg = c.alert_weak, bg = c.bg_error_weak },
+  SpellRare = { fg = c.alert_weak, bg = c.bg_error_weak },
+  
+  -- ============================================================================
+  -- Messages & Prompts
+  -- ============================================================================
+  
+  ErrorMsg = { fg = c.alert, bold = true },
+  WarningMsg = { fg = c.alert, bold = true },
+  Question = { fg = c.question, bold = true },
+  ModeMsg = { fg = c.question },
+  MoreMsg = { fg = c.question },
+  
+  -- ============================================================================
+  -- Special Characters & Whitespace
+  -- ============================================================================
+  
+  NonText = { fg = c.fg_weak },
+  EndOfBuffer = 'Comment',
+  Whitespace = 'NonText',
+  SpecialKey = 'SpecialChar',
+  Conceal = 'Noise',
+  
+  -- ============================================================================
+  -- QuickFix
+  -- ============================================================================
+  
+  QuickFixLine = { bg = c.bg_hl_special_weak, bold = true },
+  
+  -- ============================================================================
+  -- Debug
+  -- ============================================================================
+  
+  debugPC = 'ColorColumn',
+  debugBreakpoint = 'ErrorMsg',
 }