docs: document formatter collapseAttributes default change

AGENTS.md

@@ -167,7 +167,7 @@ statCntrPartsIn{...} : Int;
 local options = {
   insertSpaces = false,
   tabSize = 1,
-  collapseAttributes = true,  -- Enable attribute collapsing (default: true)
+  collapseAttributes = false,  -- Disabled by default (see note below)
   collapsePatterns = {        -- Override default patterns
     "^%s*{%s*EXTERNAL",
     "^%s*{ S7_",
@@ -178,6 +178,11 @@ local options = {
 }
 ```
 
+**Note:** `collapseAttributes` is disabled by default to preserve compatibility with the interactive toggle feature (`:SCLToggleAttrBlock`). When the formatter automatically collapses blocks, the original content is lost. To use both formatting and toggle:
+1. Format with `:LspSCLFormat` (preserves original content)
+2. Manually collapse with `:SCLCollapseAllAttrBlocks` (stores original content)
+3. Now toggle/expand works correctly
+
 ### Default Collapse Patterns
 - `^%s*{%s*EXTERNAL` - Variable attributes: `{EXTERNALACCESSIBLE := 'false'; ...}`
 - `^%s*{ S7_` - Block attributes: `{ S7_Optimized_Access := 'TRUE' }`