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

Cargo.toml

@@ -9,7 +9,7 @@ path = "src/lib.rs"
 
 [[bin]]
 name = "runner"
-path = "src/bin/runner/main.rs"
+path = "src/bin/runner.rs"
 
 [dependencies]
 anyhow = "1.0"
@@ -24,12 +24,8 @@ uuid = { version = "1.6", features = ["v4", "serde"] }
 tracing = "0.1"
 tracing-subscriber = { version = "0.3", features = ["env-filter"] }
 osiris_derive = { path = "osiris_derive" }
-rhai = { version = "1.21.0", features = ["std", "sync", "serde"], optional = true }
+rhai = { version = "1.21.0", features = ["std", "sync", "serde"] }
 env_logger = "0.10"
 
 [dev-dependencies]
 tempfile = "3.8"
-
-[features]
-default = []
-rhai-support = ["rhai"]