feat: implement storybook DSL with template composition and validation

Add complete domain-specific language for authoring narrative content for
agent simulations.

Features:
- Complete parser using LALRPOP + logos lexer
- Template composition (includes + multiple inheritance)
- Strict mode validation for templates
- Reserved keyword protection
- Semantic validators (trait ranges, schedule overlaps, life arcs, behaviors)
- Name resolution and cross-reference tracking
- CLI tool (validate, inspect, query commands)
- Query API with filtering
- 260 comprehensive tests (unit, integration, property-based)

Implementation phases:
- Phase 1 (Parser): Complete
- Phase 2 (Resolution + Validation): Complete
- Phase 3 (Public API + CLI): Complete

BREAKING CHANGE: Initial implementation

tests/examples/bidirectional_relationships.sb

@@ -0,0 +1,68 @@
+// Test bidirectional relationship resolution
+// Relationships can be declared from either participant's perspective
+
+// Simple relationship with no self/other blocks
+relationship Friendship {
+    Alice
+    Bob
+    bond: 0.8
+    years_known: 5
+}
+
+// Relationship with roles
+relationship Marriage {
+    Martha as spouse
+    David as spouse
+    bond: 0.9
+    anniversary: "2015-06-20"
+}
+
+// Relationship with self/other blocks from one perspective
+relationship ParentChild {
+    Martha as parent self {
+        responsibility: 1.0
+        protective: 0.9
+    } other {
+        dependent: 0.8
+    }
+    Tommy as child
+}
+
+// Asymmetric relationship - different roles
+relationship EmployerEmployee {
+    Martha as employer self {
+        authority: 0.9
+    } other {
+        respect: 0.8
+    }
+    Elena as employee
+}
+
+// Complex relationship with shared and participant-specific fields
+relationship RomanticPartnership {
+    Alice as partner self {
+        love: 0.95
+        trust: 0.9
+    } other {
+        attraction: 0.85
+        respect: 0.95
+    }
+    Charlie as partner
+    
+    // Shared fields
+    commitment: 0.85
+    compatibility: 0.9
+}
+
+// Multiple relationships between same people with different names
+relationship Friendship2 {
+    Alice
+    Charlie
+    bond: 0.7
+}
+
+relationship Coworkers {
+    Alice
+    Charlie
+    workplace: "TechCorp"
+}