fix: strengthen teeing and permission guidance

Author: martinfrancois

evals-reference/01-permission-and-orders/criteria.json

@@ -12,7 +12,7 @@
       "name": "Uses short-circuit permission lookup",
       "category": "stream_quality",
       "max_score": 20,
-      "description": "Checks permissions with a stream shape that short-circuits, either by flattening permissions with flatMap(...).anyMatch(...) or by using nested anyMatch/contains over each role's permissions. Do not require flatMap when nested anyMatch preserves the same behavior clearly."
+      "description": "Checks permissions with a stream shape that short-circuits, such as flatMap(...).anyMatch(...), nested anyMatch/contains, or flatMap(...).filter(...).findAny().orElseThrow(...) when it preserves the same behavior clearly."
     },
     {
       "name": "Uses IntStream range mapping",

skills/java-streams/SKILL.md

@@ -43,8 +43,9 @@ are equivalent.
    - grouping/indexing: `groupingBy`, downstream collectors, `partitioningBy`, or `toMap` with
      explicit merge/null handling.
 2. Prefer stream terminal operations that encode intent directly: `anyMatch` for existence, `count`
-   for numeric counts, `joining` for text, `min`/`max` for extremes, and primitive stream terminal
-   operations for primitive totals.
+   for numeric counts, `joining` for text, `min`/`max` for a single extreme, `teeing` for a Java
+   12+ min/max pair over the same input, and primitive stream terminal operations for primitive
+   totals.
 3. Flatten nested sources deliberately. Use `flatMap` for nested collections and
    `flatMap(Optional::stream)` on Java 9+. On Java 16+, prefer `mapMulti` for mixed subtype checks or
    small conditional emission; use primitive streams for primitive results.

skills/java-streams/references/hard-stops.md

@@ -20,6 +20,9 @@ Fix these before finalizing:
   audit calls out plain `count()` as allowed, say it is an allowed usage, not a scan hit.
 - `sorted(...).findFirst()` or sorted-then-sublist just to get one extreme. Use `min`/`max`; keep
   sorting only when the ordered list itself is required.
+- Two separate `min` and `max` stream passes over the same input when Java 12+ is available and the
+  requested result is a pair/range. Use `Collectors.teeing(minBy(...), maxBy(...), ...)` so the
+  stream states "compute these two aggregates together".
 - `map(...).collect(toList())` followed immediately by `String.join`. Use `Collectors.joining`.
 - Boxed numeric `reduce` for primitive totals/statistics. Use primitive streams or summarizing
   collectors unless the type is genuinely non-primitive, such as `BigDecimal`.

skills/java-streams/references/stream-examples.md

@@ -29,11 +29,12 @@ using APIs from [java-stream-api.md](java-stream-api.md).
   boolean anyOutOfStock = order.getItems().stream()
           .anyMatch(item -> item.getStock() == 0);
 
-  user.getRoles().stream()
+  boolean allowed = user.getRoles().stream()
           .flatMap(role -> role.getPermissions().stream())
-          .filter(requiredPermission::equals)
-          .findAny()
-          .orElseThrow(AccessDeniedException::new);
+          .anyMatch(requiredPermission::equals);
+  if (!allowed) {
+      throw new AccessDeniedException();
+  }
   ```
 
 - Flatten present optionals on Java 9+:
@@ -146,7 +147,8 @@ Map<Boolean, List<Product>> partitionedProducts = products.stream()
         .collect(Collectors.partitioningBy(product -> product.getStock() > 0));
 ```
 
-Java 12+ `teeing` can combine two reductions:
+Java 12+ `teeing` can combine two independent reductions over the same input. Prefer this for a
+min/max pair or price range instead of running two separate stream passes:
 
 ```java
 Pair<Product, Product> priceRange = products.stream()