docs: teach the graph generator the CHAINED fused-dispatch spelling

ds-review-bot round-3 finding: agentEvents(ctx, agent).emit(...) has a
call-expression receiver the generator's identifier check missed, silently
dropping agent-loop as agent/session-start's producer. The generator now
recognizes a call receiver whose callee is agentEvents; graph regenerated
with the producer edge restored.

scripts/gen-doc-graphs.ts

@@ -519,6 +519,11 @@ function collectEventRelations(): Map<string, EventRelation> {
 }
 
 function isCordisContextReceiver(expr: ts.PropertyAccessExpression, sf: ts.SourceFile): boolean {
+  // The chained fused-dispatch spelling: `agentEvents(ctx, agent).emit(…)` —
+  // the receiver is a call expression, not an identifier.
+  if (ts.isCallExpression(expr.expression) && expr.expression.expression.getText(sf) === 'agentEvents') {
+    return true
+  }
   const target = expr.expression.getText(sf)
   if (target === 'ctx' || target === 'this.ctx') return true
   // Scoped-dispatch spellings (the agent-scoping seam): the loop's fused