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/behavior_and_lifearc.sb

@@ -0,0 +1,50 @@
+// Test behavior trees and life arcs
+
+life_arc Childhood {
+    state infant {
+        on ready -> toddler
+    }
+    state toddler {
+        on ready -> child
+    }
+    state child {
+        on ready -> teen
+    }
+}
+
+behavior SimpleBehavior {
+    walk_around
+}
+
+behavior SequenceBehavior {
+    > {
+        check_energy
+        move_to_location
+        perform_action
+    }
+}
+
+behavior SelectorBehavior {
+    ? {
+        try_option_a
+        try_option_b
+        fallback
+    }
+}
+
+behavior NestedBehavior {
+    > {
+        ? {
+            check_condition_a
+            check_condition_b
+        }
+        perform_action
+    }
+}
+
+behavior WithSubtree {
+    > {
+        @helpers::check_preconditions
+        main_action
+    }
+}