feat: Implement scene rulebook and validation engine

- Added a new SceneRulebook system to manage data-driven validation rules for actions.
- Introduced rule checks for actions like "take", "open", "move", "introduce", and "describe".
- Created a rulebook engine to evaluate conditions and enforce rules during action validation.
- Enhanced action handling with support for scene entry and character descriptions.
- Updated the architecture documentation to reflect the new rule-based validation approach.
- Added new endpoints and improved the persistence layer for rulebooks.

charactergarden/app/src/contracts/rulebook.ts

@@ -0,0 +1,94 @@
+/**
+ * SceneRulebook — data-driven validation rules for the truth engine.
+ *
+ * Rules are stored per-scene in the database and evaluated by rulebookEngine.ts.
+ * The default set is seeded from defaultRulebook.ts and mirrors the original
+ * hardcoded logic in truthEngine.ts.
+ */
+
+/** Which entity in the action context a condition refers to. */
+export type EntityRole = "actor" | "target" | "actorRoom" | "targetRoom";
+
+/**
+ * A composable, JSON-serialisable condition expression.
+ *
+ * Combinators: and | or | not
+ * Predicates:
+ *   entityExists              — entity referenced by role is present in world state
+ *   entityExistsOrWillBeCreated — entity exists OR will be created earlier in this turn
+ *   entityType                — entity.type === requiredType
+ *   eq / neq                  — entity field comparison (id, name, type, or attributes[attribute])
+ *   attributeExists           — entity.attributes[attribute] is not undefined
+ *   sameLocation              — two entities share the same location attribute value
+ *   actorIdIn                 — action.actorId is included in an allowed list
+ *   actorNameIn               — actor.name matches one of an allowed list (case-insensitive)
+ *   attributeRef              — entities[checkRole].attributes[prefix + entities[refRole].attributes[refAttribute]] === true
+ *   metaValueNotInRoom        — no entity of entityType in actor's room has name === action.metadata[metaKey]
+ */
+export type ConditionExpr =
+  | { op: "and"; conditions: ConditionExpr[] }
+  | { op: "or"; conditions: ConditionExpr[] }
+  | { op: "not"; condition: ConditionExpr }
+  | { op: "entityExists"; role: EntityRole }
+  | { op: "entityExistsOrWillBeCreated"; role: EntityRole }
+  | { op: "entityType"; role: EntityRole; requiredType: string }
+  | { op: "eq"; role: EntityRole; attribute: string; value: unknown }
+  | { op: "neq"; role: EntityRole; attribute: string; value: unknown }
+  | { op: "attributeExists"; role: EntityRole; attribute: string }
+  | { op: "sameLocation"; roleA: EntityRole; roleB: EntityRole }
+  | { op: "actorIdIn"; allowedIds: string[] }
+  | { op: "actorNameIn"; allowedNames: string[] }
+  | {
+      op: "attributeRef";
+      /** Entity whose attribute is being tested */
+      checkRole: EntityRole;
+      /** Optional string prepended to the resolved key (e.g. "has_") */
+      prefix?: string;
+      /** Entity that provides the dynamic attribute name */
+      refRole: EntityRole;
+      /** Attribute on refRole whose value supplies the key name */
+      refAttribute: string;
+    }
+  | {
+      op: "metaValueNotInRoom";
+      /** Key in action.metadata whose value to match against entity names */
+      metaKey: string;
+      /** Only match entities of this type */
+      entityType: string;
+    };
+
+/** A single named check within an action rule set. */
+export type RuleCheck = {
+  id: string;
+  /** Human-readable label shown in the rulebook editor. */
+  description: string;
+  condition: ConditionExpr;
+  failReason: string;
+  /**
+   * Failure message template.
+   * Supports: {actor.id}, {actor.name}, {target.id}, {target.name}
+   */
+  failMessage: string;
+};
+
+/** All checks that apply to a specific action type. */
+export type ActionRuleSet = {
+  actionType: string;
+  /**
+   * When false, all checks are skipped and the action always passes.
+   * Useful for quickly disabling enforcement without deleting the rules.
+   */
+  enabled: boolean;
+  checks: RuleCheck[];
+};
+
+/** The full rulebook attached to a scene/world. */
+export type SceneRulebook = {
+  id: string;
+  worldId: string;
+  name: string;
+  description?: string;
+  rules: ActionRuleSet[];
+  createdAt: number;
+  updatedAt: number;
+};