fix(runtime): Random.* in any program; value_* called directly brings the value tree

The seeded random numbers lived in the ECS runtime, so a tool or a
program of test blocks got "unknown function rng_range". They are
runtime/native/rng.ludic now, spliced on Random.* or a bare rng_*/seed
call nobody defines, and imported by core.ludic for a game. A bare
value_*/json_* call nothing in the program defines splices the value
tree the way Value.* does. Reseed.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

examples/library/value_direct.ludic

@@ -0,0 +1,11 @@
+# value_direct.ludic — the value tree is spliced when a program calls value_* / json_* itself,
+# as a package does, not only when it writes Value.* or Json.*.
+#
+# Running it prints:  {"fish":3} 3
+program ValueDirect {
+  entry {
+    let o = value_object()
+    value_put(o, "fish", value_int(3))
+    print(`{json_encode(o)} {value_as_int(value_get(o, "fish"))}`)
+  }
+}