feat(Mountain/Shim): Add TypeConverter module structure for IPC data conversion

- Creates module declarations mirroring TypeScript `cocoon-type-converters` structure in Rust
- Establishes foundation for type-safe serialization between `Mountain` and `Cocoon` processes via `Vine` IPC
- Prepares conversion logic for VS Code extension API surface areas including CodeActions, Completions, and WorkspaceEdits
- Enables future implementation of bidirectional type mapping as part of MVP Path A's extension support
- Aligns with recent ProtoValueConverter work (d271a2b) to handle complex IPC data structures
- Includes Notebook type conversions for potential future expansion of supported extension capabilities

Author: NikolaRHristov

Source/Shim/TypeConverter/mod.rs

@@ -0,0 +1,16 @@
+// File: Shim/TypeConverter/mod.rs
+// This module file is conceptual for Rust, as the `cocoon-type-converters`
+// directory exists in the TypeScript codebase. In a parallel Rust structure,
+// this would declare and re-export converter modules.
+
+#![allow(non_snake_case, non_camel_case_types)]
+
+// In a Rust implementation, this `mod.rs` would look something like this:
+mod CodeAction;
+mod Completion;
+mod LanguageFeature;
+mod Main;
+mod Notebook; // Added for completeness
+mod WorkspaceEdit;
+
+pub use self::{CodeAction::*, Completion::*, LanguageFeature::*, Main::*, Notebook::*, WorkspaceEdit::*};