Refactor Rhai integration with context-based execution and type registry

Major Changes:
- Moved Rhai support from rhai_support/ to rhai/ module
- Implemented context-based execution with signatory access control
- Added TypeRegistry for dynamic type registration and object creation
- Refactored engine to use context (Vec<String>) instead of instance
- Removed old runner binary (moved to runner_rust crate)

Rhai Module:
- engine.rs: Core Rhai engine with context-based get_context()
- functions.rs: Rhai function bindings (create_note, create_event, etc.)
- mod.rs: Module exports and organization

Store Improvements:
- TypeRegistry for registering object types and creators
- Generic store uses type registry for dynamic object creation
- Improved error handling and type safety

Documentation:
- RHAI_REFACTOR_COMPLETE.md: Refactoring details
- SIGNATORY_ACCESS_CONTROL.md: Context-based access control
- TYPE_REGISTRY_DESIGN.md: Type registry architecture
- REFACTORING_COMPLETE.md: Overall refactoring summary
- TESTS_COMPLETE.md: Testing documentation

Build Status: ✅ Compiles successfully with minor warnings

src/lib.rs

@@ -8,16 +8,14 @@ pub mod interfaces;
 pub mod objects;
 pub mod retrieve;
 pub mod store;
-
-#[cfg(feature = "rhai-support")]
-pub mod rhai_support;
+pub mod rhai;
 
 pub use error::{Error, Result};
 pub use store::{BaseData, IndexKey, Object, Storable};
+pub use objects::{Event, Note};
+
+// OsirisContext is the main type for Rhai integration
+pub use rhai::{OsirisContext, OsirisInstance};
 
 // Re-export the derive macro
 pub use osiris_derive::Object as DeriveObject;
-
-// OsirisInstance is the main type for Rhai integration
-#[cfg(feature = "rhai-support")]
-pub use rhai_support::OsirisInstance;