fix: record affected documents at change time

Edits queue their path; before the next snapshot the engine walks dependents with a frozen copy of every recorded view (each dependent on the graph stack) and stamps affected documents with a sequence. Consumers read them via changes_since(cursor), so queries in between cannot absorb a change. Graph dictionary views now cover the combined import list, matching first-wins resolution.

bindings/nodejs/index.d.ts

@@ -118,6 +118,10 @@ export type PolicySlotState =
   | 'path';
 export type PolicySlotRole = 'unary' | 'condition' | 'value' | 'path';
 /** One enum value: `label` for display, `source` the ready-to-splice ZEN literal (null when unquotable). */
+export interface PolicyChanges {
+  cursor: number
+  paths: Array<string>
+}
 export interface PolicyValueOption {
   value: string;
   label: string;
@@ -400,7 +404,7 @@ export declare class Workspace {
   isGraph(path: string): boolean
   uncheckedNodes(path: string): Array<string>
   paths(): Array<string>
-  affectedBy(paths: Array<string>): Array<string>
+  changesSince(cursor: number): PolicyChanges
   updateBlock(req: PolicyUpdateBlockRequest): void
   removeBlock(req: PolicyRemoveBlockRequest): boolean
   diagnostics(policyPath: string, maxDiagnostics?: number | undefined | null): Array<PolicyDiagnostic>

bindings/nodejs/src/policy.rs

@@ -12,6 +12,12 @@ use zen_engine::workspace;
 
 type ResolverRef = FunctionRef<FnArgs<(String, Value)>, Option<String>>;
 
+#[napi(object)]
+pub struct PolicyChanges {
+    pub cursor: i64,
+    pub paths: Vec<String>,
+}
+
 #[napi(object)]
 pub struct PolicyExpressionCursor {
     pub policy_path: String,
@@ -627,13 +633,12 @@ impl Workspace {
     }
 
     #[napi]
-    pub fn affected_by(&self, paths: Vec<String>) -> Vec<String> {
-        let paths: Vec<&str> = paths.iter().map(String::as_str).collect();
-        self.inner
-            .affected_by(&paths)
-            .into_iter()
-            .map(|p| p.to_string())
-            .collect()
+    pub fn changes_since(&self, cursor: i64) -> PolicyChanges {
+        let (next, paths) = self.inner.changes_since(cursor.max(0) as u64);
+        PolicyChanges {
+            cursor: next as i64,
+            paths: paths.into_iter().map(|p| p.to_string()).collect(),
+        }
     }
 
     #[napi]