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

src/main.lua

@@ -296,7 +296,7 @@ function handlers.textDocument_hover(params)
 			contents = { kind = "markdown", value = detail },
 			range = {
 				start = { line = params.position.line, character = word_start - 1 },
-				endPos = { line = params.position.line, character = word_end - 1 },
+				["end"] = { line = params.position.line, character = word_end - 1 },
 			},
 		}
 	end
@@ -315,7 +315,7 @@ function handlers.textDocument_hover(params)
 					contents = { kind = "markdown", value = detail },
 					range = {
 						start = { line = params.position.line, character = word_start - 1 },
-						endPos = { line = params.position.line, character = word_end - 1 },
+						["end"] = { line = params.position.line, character = word_end - 1 },
 					},
 				}
 			end
@@ -449,7 +449,7 @@ function handlers.textDocument_definition(params)
 			uri = uri,
 			range = {
 				start = { line = pos.line, character = pos.character },
-				endPos = { line = pos.line, character = pos.character + #word },
+				["end"] = { line = pos.line, character = pos.character + #word },
 			},
 		}
 	end
@@ -478,10 +478,10 @@ function handlers.textDocument_documentSymbol(params)
 			table.insert(symbols, {
 				name = func.kind:upper() .. " " .. func.name,
 				kind = kind_map[func.kind] or 14,
-				range = { start = { line = func.start, character = 0 }, endPos = { line = func.final, character = 0 } },
+				range = { start = { line = func.start, character = 0 }, ["end"] = { line = func.final, character = 0 } },
 				selectionRange = {
 					start = { line = func.start, character = 0 },
-					endPos = { line = func.start, character = #func.name },
+					["end"] = { line = func.start, character = #func.name },
 				},
 				containerName = nil,
 			})
@@ -500,11 +500,11 @@ function handlers.textDocument_documentSymbol(params)
 				detail = var_info.type or "VAR",
 				range = {
 					start = { line = var_info.line, character = 0 },
-					endPos = { line = var_info.line, character = #var_name },
+					["end"] = { line = var_info.line, character = #var_name },
 				},
 				selectionRange = {
 					start = { line = var_info.line, character = var_info.character },
-					endPos = { line = var_info.line, character = var_info.character + #var_name },
+					["end"] = { line = var_info.line, character = var_info.character + #var_name },
 				},
 				containerName = nil,
 			})
@@ -526,11 +526,11 @@ function handlers.textDocument_documentSymbol(params)
 				detail = detail,
 				range = {
 					start = { line = type_info.start_line or 0, character = 0 },
-					endPos = { line = type_info.start_line or 0, character = #type_name },
+					["end"] = { line = type_info.start_line or 0, character = #type_name },
 				},
 				selectionRange = {
 					start = { line = type_info.start_line or 0, character = 0 },
-					endPos = { line = type_info.start_line or 0, character = #type_name },
+					["end"] = { line = type_info.start_line or 0, character = #type_name },
 				},
 				containerName = nil,
 			})
@@ -656,6 +656,10 @@ function handlers.textDocument_semanticTokensRange(params)
 	return handlers.textDocument_semanticTokensFull(params)
 end
 
+-- Aliases for method names with slashes converted to underscores
+handlers["textDocument_semanticTokens_full"] = handlers.textDocument_semanticTokensFull
+handlers["textDocument_semanticTokens_range"] = handlers.textDocument_semanticTokensRange
+
 function handlers.textDocument_inlayHint(params)
 	local uri = params.textDocument.uri
 	local doc = documents[uri]
@@ -708,7 +712,7 @@ function handlers.workspace_symbol(params)
 				uri = uri,
 				range = {
 					start = { line = line, character = col },
-					endPos = { line = line, character = col + length },
+					["end"] = { line = line, character = col + length },
 				},
 			},
 		})
@@ -848,17 +852,26 @@ local function handle_message(message)
 	if message.method == "$/cancelRequest" then
 		return nil
 	end
-	local handler = handlers[message.method]
+	-- Convert method name from "textDocument/didOpen" to "textDocument_didOpen"
+	local method_name = message.method:gsub("/", "_")
+	local handler = handlers[method_name]
 	if handler then
 		local ok, result = pcall(handler, message.params)
-		if ok then
-			return { id = message.id, result = result }
-		else
-			return { id = message.id, error = { code = -32603, message = tostring(result) } }
+		-- Only return response for requests (have id), not notifications
+		if message.id then
+			if ok then
+				return { id = message.id, result = result }
+			else
+				return { id = message.id, error = { code = -32603, message = tostring(result) } }
+			end
 		end
 	else
-		return { id = message.id, error = { code = -32601, message = "Method not found: " .. message.method } }
+		-- Only return error for requests (have id)
+		if message.id then
+			return { id = message.id, error = { code = -32601, message = "Method not found: " .. message.method } }
+		end
 	end
+	return nil
 end
 
 local function main()
@@ -871,6 +884,9 @@ local function main()
 		if not line then
 			break
 		end
+		-- Strip trailing \r (Windows line endings)
+		line = line:gsub("\r$", "")
+		
 		if line:match("^Content%-Length:%s*(%d+)") then
 			content_length = tonumber(line:match("^Content%-Length:%s*(%d+)"))
 		elseif line == "" then