Refactor PLCopen generated structures to use Box for inline elements, enhancing memory management and performance. Added detailed FBD analysis implementation plan and examples for testing FBD, LD, and ST/IL extraction. Introduced new tests for FBD parsing and reference extraction, ensuring comprehensive coverage of graphical languages in PLCopen projects.

Author: radevgit

.github/copilot-instructions.md

@@ -0,0 +1,26 @@
+my name is `zoo`
+
+## Project Overview
+
+This is a Rust workspace for parsing and analyzing PCL programming files.
+
+**Primary goal:** Build tools for PLC code analysis, starting with a **Code Smell Detector / Static Analyzer**.
+
+### Error Handling
+- Permissive parsing: continue on non-critical errors
+- Log warnings for unexpected content
+- Use enum-based errors (not `String` in `Err`)
+- dont use `panic!` in code, only in tests
+
+## GIT
+- do not commit in git, except explicitely asked
+
+## When Helping with This Project
+
+1. **Check existing docs first** - Many decisions are documented in `docs/`
+2. **Use existing patterns** - Follow the XSD parser/codegen structure
+3. **Test with real files** - Use files in `~/devpublic/dataplc/` directory
+4. **Specificantion documents** - `~/devpublic/specs/`
+
+
+