feat(lsp): add call hierarchy support for TCL and MOM

Adds LSP call hierarchy support for TCL procedures and MOM events.
A symbol index and identity logic underpin incoming and outgoing calls.
LSP call hierarchy features are wired and changelog/README updated.

- Implement data encoding for call hierarchy items and identity restoration
- Wire LSP server to expose prepare_call_hierarchy, incoming_calls, and outgoing_calls
- Add tests for cross-file calls and edge cases

README.md

@@ -10,6 +10,7 @@ A comprehensive VS Code extension providing language support and remote debuggin
 - **Intelligent Code Analysis** - Linting and error detection for postprocessor code
 - **Auto-completion** - Context-aware code completion for faster development
 - **Signature Help** - Shows parameters and documentation for custom and NX procedures
+- **Call Hierarchy** - Traces incoming and outgoing calls between custom TCL procedures and MOM event handlers
 - **NX Tcl Remote Debugger** - Breakpoints, stepping, call stack, scopes, variables, watches, evaluation, logpoints, hit conditions, and Tcl error stops directly in a running NX Post process
 
 ## Supported File Types
@@ -96,6 +97,7 @@ Simply open any supported file type and enjoy:
 - Code formatting (Format Document command)
 - Hover information
 - Signature help while entering procedure arguments
+- Incoming and outgoing call hierarchy for custom procedures and MOM event handlers
 - Remote NX Tcl debugging with breakpoints and full stepping
 
 ## Contributing