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/diagnostics.lua

@@ -1,6 +1,21 @@
 -- SCL Diagnostics - Linter functionality for the LSP server
 local M = {}
-local parser = require("scl_lsp.parser")
+
+-- Get script path for loading parser (same pattern as main.lua)
+local script_path = debug.getinfo(1, "S").source:gsub("^@", ""):match("(.*/)") or ""
+if script_path == "" then
+  script_path = "."
+end
+if script_path:sub(1, 1) ~= "/" then
+  local cwd = io.popen("pwd")
+  if cwd then
+    script_path = cwd:read("*l") .. "/" .. script_path
+    cwd:close()
+  end
+end
+package.path = package.path .. ";" .. script_path .. "/?.lua"
+
+local parser = dofile(script_path .. "/parser.lua")
 
 local DiagnosticSeverity = {
   Error = 1,
@@ -19,7 +34,7 @@ end
 local function range_to_lsp(start_line, start_char, end_line, end_char)
   return {
     start = position_to_lsp(start_line, start_char),
-    end = position_to_lsp(end_line, end_char),
+    ["end"] = position_to_lsp(end_line, end_char),
   }
 end