feat(parser): add action parameters, repeater decorator, and named participants

Add syntax enhancements for more expressive behavior trees and relationships.

Action parameters:
- Support typed/positional parameters: WaitDuration(2.0)
- Support named parameters: SetValue(field: value)
- Enable inline values without field names

Repeater decorator:
- Add * { node } syntax for repeating behavior nodes
- Maps to Decorator("repeat", node)

Named participant blocks:
- Replace self/other blocks with named participant syntax
- Support multi-party relationships
- Example: Alice { role: seeker } instead of self { role: seeker }

Schedule block syntax:
- Require braces for schedule blocks to support narrative fields
- Update tests to use new syntax: 04:00 -> 06:00: Activity { }

src/syntax/ast.rs

@@ -52,6 +52,7 @@ pub enum UseKind {
 #[derive(Debug, Clone, PartialEq)]
 pub struct Character {
     pub name: String,
+    pub species: Option<String>, // `: Species` - what the character fundamentally is
     pub fields: Vec<Field>,
     pub template: Option<Vec<String>>, // `from Template1, Template2`
     pub span: Span,
@@ -142,6 +143,7 @@ pub struct LifeArc {
 #[derive(Debug, Clone, PartialEq)]
 pub struct ArcState {
     pub name: String,
+    pub on_enter: Option<Vec<Field>>,
     pub transitions: Vec<Transition>,
     pub span: Span,
 }
@@ -166,6 +168,7 @@ pub struct ScheduleBlock {
     pub start: Time,
     pub end: Time,
     pub activity: String,
+    pub fields: Vec<Field>,
     pub span: Span,
 }
 
@@ -225,6 +228,7 @@ pub struct Location {
 #[derive(Debug, Clone, PartialEq)]
 pub struct Species {
     pub name: String,
+    pub includes: Vec<String>,
     pub fields: Vec<Field>,
     pub span: Span,
 }