datalog: Phase 6 adornments + SIPS analysis (194/194)

New lib/datalog/magic.sx — first piece of magic-sets:

  dl-adorn-arg arg bound          → "b" or "f"
  dl-adorn-args args bound        → adornment string
  dl-adorn-goal goal              → adornment under empty bound set
  dl-adorn-lit lit bound          → adornment of any literal
  dl-vars-bound-by-lit lit bound  → free vars this lit will bind
  dl-init-head-bound head adn     → bound set seeded from head adornment
  dl-rule-sips rule head-adn      → ({:lit :adornment} ...) per body lit

SIPS walks left-to-right tracking the bound set; recognises `is` and
aggregate result-vars as new binders, lets comparisons and negation
pass through with computed adornments.

Inspection-only — saturator doesn't yet consume these. Lays
groundwork for a future magic-sets transformation.

10 new tests cover pure adornment, SIPS over a chain rule,
head-fully-bound rules, comparisons, and `is`. Total 194/194.

lib/datalog/scoreboard.json

@@ -1,8 +1,8 @@
 {
   "lang": "datalog",
-  "total_passed": 184,
+  "total_passed": 194,
   "total_failed": 0,
-  "total": 184,
+  "total": 194,
   "suites": [
     {"name":"tokenize","passed":26,"failed":0,"total":26},
     {"name":"parse","passed":18,"failed":0,"total":18},
@@ -13,7 +13,8 @@
     {"name":"negation","passed":10,"failed":0,"total":10},
     {"name":"aggregates","passed":18,"failed":0,"total":18},
     {"name":"api","passed":14,"failed":0,"total":14},
+    {"name":"magic","passed":10,"failed":0,"total":10},
     {"name":"demo","passed":18,"failed":0,"total":18}
   ],
-  "generated": "2026-05-08T09:47:44+00:00"
+  "generated": "2026-05-08T09:50:50+00:00"
 }