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/equality.sb

@@ -0,0 +1,40 @@
+// Test equality expressions in life arcs
+
+life_arc NameCheck {
+    state checking {
+        on name is "Alice" -> found_alice
+        on name is "Bob" -> found_bob
+    }
+    state found_alice {
+        on ready -> checking
+    }
+    state found_bob {
+        on ready -> checking
+    }
+}
+
+life_arc StatusCheck {
+    state monitoring {
+        on status is active -> active_state
+        on status is inactive -> inactive_state
+    }
+    state active_state {
+        on status is inactive -> inactive_state
+    }
+    state inactive_state {
+        on status is active -> active_state
+    }
+}
+
+life_arc FlagCheck {
+    state idle {
+        on completed is true -> done
+        on completed is false -> working
+    }
+    state working {
+        on completed is true -> done
+    }
+    state done {
+        on completed is false -> working
+    }
+}