datalog: findall aggregate (159/159)

(findall L V Goal) — bind L to the distinct V values for which Goal
holds, or the empty list when none. One-line addition to
dl-do-aggregate that returns the unreduced list. Tests cover EDB,
derived relation, and empty cases.

Useful for "give me all the X such that ..." queries without
scalar reduction.

lib/datalog/scoreboard.json

@@ -1,8 +1,8 @@
 {
   "lang": "datalog",
-  "total_passed": 156,
+  "total_passed": 159,
   "total_failed": 0,
-  "total": 156,
+  "total": 159,
   "suites": [
     {"name":"tokenize","passed":26,"failed":0,"total":26},
     {"name":"parse","passed":18,"failed":0,"total":18},
@@ -11,9 +11,9 @@
     {"name":"builtins","passed":19,"failed":0,"total":19},
     {"name":"semi_naive","passed":8,"failed":0,"total":8},
     {"name":"negation","passed":10,"failed":0,"total":10},
-    {"name":"aggregates","passed":10,"failed":0,"total":10},
+    {"name":"aggregates","passed":13,"failed":0,"total":13},
     {"name":"api","passed":9,"failed":0,"total":9},
     {"name":"demo","passed":10,"failed":0,"total":10}
   ],
-  "generated": "2026-05-08T08:57:57+00:00"
+  "generated": "2026-05-08T09:02:31+00:00"
 }