fix(lsp): Fix LSP server attachment and JSON parsing issues

- Replace lspconfig.scl_lsp registration with vim.lsp.start() + FileType autocmd
  for Neovim 0.11+ compatibility
- Fix Lua reserved keyword 'end' in tables (use bracket notation ['end'])
- Fix JSON decoder pattern matching bugs (s:find -> s:sub:match)
- Add LSP method name conversion (textDocument/didOpen -> textDocument_didOpen)
- Handle request vs notification correctly (only respond to requests with id)
- Strip CRLF line endings for Windows compatibility
- Add semantic token handler aliases
- Update documentation with implementation notes

lua/scl_lsp/init.lua

@@ -13,51 +13,54 @@ function M.setup(opts)
   setup_package_path()
   opts = opts or {}
 
-  local lspconfig_avail, lspconfig = pcall(require, "lspconfig")
-  if not lspconfig_avail then
-    vim.notify("lspconfig not found. Please install nvim-lspconfig.", vim.log.levels.ERROR)
-    return
-  end
-
   local server_path = opts.server_path or vim.fn.expand("~/dev/scl_lsp/src/main.lua")
-
+  
   local root_patterns = { ".git", "data_types", "plc.data.json" }
-  local function get_root_dir(fname)
-    local root = vim.fs.root(fname, root_patterns)
-    return root or vim.fn.fnamemodify(fname, ":h")
-  end
-
-  local function on_attach(client, bufnr)
-    if opts.lsp and opts.lsp.on_attach then
-      opts.lsp.on_attach(client, bufnr)
-    end
-
-    if opts.lsp.formatting then
-      vim.api.nvim_buf_create_user_command(bufnr, "LspSCLFormat", function()
-        vim.lsp.buf.format({ name = "scl-language-server" })
-      end, {})
-    end
-  end
-
-  lspconfig.scl_lsp = {
-    default_config = {
-      name = "scl-language-server",
+  
+  local function start_lsp(bufnr)
+    local fname = vim.api.nvim_buf_get_name(bufnr)
+    if fname == "" then return end
+    
+    local root_dir = vim.fs.root(fname, root_patterns)
+      or vim.fn.fnamemodify(fname, ":p:h")
+    
+    vim.lsp.start({
+      name = "scl_lsp",
       cmd = { "lua", server_path },
-      filetypes = { "scl" },
-      root_dir = get_root_dir,
-      settings = {},
-      on_attach = on_attach,
-    },
-    docs = {
-      description = "Language server for Siemens SCL (LSP, Linter, Formatter)",
-      default_config = {
-        name = "scl-language-server",
-        cmd = { "lua", server_path },
-        filetypes = { "scl" },
-        root_dir = "root_pattern('.git', 'data_types', 'plc.data.json')",
-      },
-    },
-  }
+      root_dir = root_dir,
+      on_attach = function(client, b)
+        if opts.lsp and opts.lsp.on_attach then
+          opts.lsp.on_attach(client, b)
+        end
+        
+        if opts.lsp and opts.lsp.formatting then
+          vim.api.nvim_buf_create_user_command(b, "LspSCLFormat", function()
+            vim.lsp.buf.format({ name = "scl_lsp" })
+          end, {})
+        end
+      end,
+    })
+  end
+  
+  -- Create FileType autocmd for future buffers
+  vim.api.nvim_create_autocmd("FileType", {
+    pattern = "scl",
+    callback = function(args)
+      start_lsp(args.buf)
+    end,
+  })
+  
+  -- Create global format command (works on current buffer)
+  vim.api.nvim_create_user_command("LspSCLFormat", function()
+    vim.lsp.buf.format({ name = "scl_lsp" })
+  end, {})
+  
+  -- Start LSP for any existing scl buffers (handles lazy loading case)
+  for _, bufnr in ipairs(vim.api.nvim_list_bufs()) do
+    if vim.bo[bufnr].filetype == "scl" and vim.api.nvim_buf_is_loaded(bufnr) then
+      start_lsp(bufnr)
+    end
+  end
 
   M.setup_syntax(opts)
   M.setup_multiline_params()