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/override_values.sb

@@ -0,0 +1,89 @@
+// Test override as field values
+
+template HumanNeeds {
+    sleep: 0.8
+    food: 0.7
+    social: 0.5
+    health: 0.6
+}
+
+template BakerSchedule {
+    work_start: 6
+    work_end: 14
+    lunch_time: 12
+}
+
+// Override in field value - set operations
+character Alice {
+    name: "Alice"
+    needs: @HumanNeeds {
+        sleep: 0.9
+        social: 0.7
+    }
+}
+
+// Override with remove operation
+character Bob {
+    name: "Bob"
+    needs: @HumanNeeds {
+        remove social
+        sleep: 0.6
+    }
+}
+
+// Override with append operation
+character Carol {
+    name: "Carol"
+    needs: @HumanNeeds {
+        append creativity: 0.8
+        food: 0.9
+    }
+}
+
+// Override with mixed operations
+character David {
+    name: "David"
+    needs: @HumanNeeds {
+        sleep: 0.95
+        remove social
+        append exercise: 0.7
+    }
+}
+
+// Multiple overrides in same character
+character Elena {
+    name: "Elena"
+    needs: @HumanNeeds {
+        sleep: 0.7
+        food: 0.8
+    }
+    daily_schedule: @BakerSchedule {
+        work_start: 5
+        remove lunch_time
+    }
+}
+
+// Empty override (inherits all)
+character Frank {
+    name: "Frank"
+    needs: @HumanNeeds {
+    }
+}
+
+// Only removes
+character Grace {
+    name: "Grace"
+    needs: @HumanNeeds {
+        remove sleep
+        remove food
+    }
+}
+
+// Only appends
+character Henry {
+    name: "Henry"
+    needs: @HumanNeeds {
+        append rest: 0.5
+        append work: 0.8
+    }
+}