refactor: modularize nvim config into lua/config + lua/plugins

- Extract all options, keymaps, and autocommands into lua/config/
- Move every plugin spec into its own file under lua/plugins/
- Add custom inline orng colorscheme (dark + light) synced to macOS appearance
- Consolidate image.nvim into pdf-viewer.lua (fix duplicate spec)
- Fix image.nvim processor: magick -> magick_cli
- Remove conflicting nvim-autopairs (kept mini.pairs)
- Fix broken <C-f> keymap (was calling non-existent builtin cmd)
- Delete lua/kickstart/ and lua/custom/ folders
- Add colors/orng.vim + colors/orng-light.vim stubs for mid-session switching
- init.lua reduced from 1078 lines to 49 lines

lua/plugins/debug.lua

@@ -0,0 +1,75 @@
+-- lua/plugins/debug.lua
+-- DAP debugging: Go + PHP/Xdebug support
+
+return {
+  'mfussenegger/nvim-dap',
+  dependencies = {
+    'rcarriga/nvim-dap-ui',
+    'nvim-neotest/nvim-nio',
+    'mason-org/mason.nvim',
+    'jay-babu/mason-nvim-dap.nvim',
+    'leoluz/nvim-dap-go',
+    'nvim-telescope/telescope-dap.nvim',
+  },
+  keys = {
+    { '<F5>',      function() require('dap').continue() end,                               desc = 'Debug: Start/Continue' },
+    { '<F1>',      function() require('dap').step_into() end,                              desc = 'Debug: Step Into' },
+    { '<F2>',      function() require('dap').step_over() end,                              desc = 'Debug: Step Over' },
+    { '<F3>',      function() require('dap').step_out() end,                               desc = 'Debug: Step Out' },
+    { '<F7>',      function() require('dapui').toggle() end,                               desc = 'Debug: Toggle UI' },
+    { '<leader>b', function() require('dap').toggle_breakpoint() end,                      desc = 'Debug: Toggle Breakpoint' },
+    { '<leader>B', function() require('dap').set_breakpoint(vim.fn.input 'Condition: ') end, desc = 'Debug: Set Conditional Breakpoint' },
+    { '<leader>dv', function() require('telescope').extensions.dap.variables() end,       desc = 'Debug: Find [V]ariables' },
+    { '<leader>df', function() require('telescope').extensions.dap.frames() end,          desc = 'Debug: Find [F]rames' },
+    { '<leader>dc', function() require('telescope').extensions.dap.commands() end,        desc = 'Debug: Find [C]ommands' },
+    { '<leader>db', function() require('telescope').extensions.dap.list_breakpoints() end, desc = 'Debug: List [B]reakpoints' },
+  },
+  config = function()
+    local dap    = require 'dap'
+    local dapui  = require 'dapui'
+
+    require('mason-nvim-dap').setup {
+      automatic_installation = true,
+      handlers = {},
+      ensure_installed = { 'delve', 'php-debug-adapter' },
+    }
+
+    dapui.setup {
+      icons = { expanded = '▾', collapsed = '▸', current_frame = '*' },
+      controls = {
+        icons = {
+          pause = '⏸', play = '▶', step_into = '⏎', step_over = '⏭',
+          step_out = '⏮', step_back = 'b', run_last = '▶▶',
+          terminate = '⏹', disconnect = '⏏',
+        },
+      },
+    }
+
+    -- Auto-open/close dapui with debug sessions
+    dap.listeners.after.event_initialized['dapui_config']  = dapui.open
+    dap.listeners.before.event_terminated['dapui_config']  = dapui.close
+    dap.listeners.before.event_exited['dapui_config']      = dapui.close
+
+    -- Go
+    require('dap-go').setup {
+      delve = { detached = vim.fn.has 'win32' == 0 },
+    }
+
+    -- PHP / Xdebug
+    dap.adapters.php = {
+      type    = 'executable',
+      command = 'node',
+      args    = { vim.fn.stdpath 'data' .. '/mason/packages/php-debug-adapter/extension/out/phpDebug.js' },
+    }
+    dap.configurations.php = {
+      { type = 'php', request = 'launch', name = 'Listen for Xdebug',        port = 9003 },
+      { type = 'php', request = 'launch', name = 'Listen for Xdebug (DDEV)', port = 9003,
+        pathMappings = { ['/var/www/html'] = '${workspaceFolder}' } },
+      { type = 'php', request = 'launch', name = 'Run current script',       port = 9003,
+        cwd = '${fileDirname}', program = '${file}', runtimeExecutable = 'php' },
+    }
+
+    -- Telescope DAP extension
+    require('telescope').load_extension 'dap'
+  end,
+}