datalog-plan: log parser/safety bug-hunt round (7 bugs fixed)

plans/datalog-on-sx.md

@@ -15,7 +15,7 @@ for rose-ash data (e.g. federation graph, content relationships).
 
 ## Status (rolling)
 
-`bash lib/datalog/conformance.sh` → **239/239 across 11 suites**
+`bash lib/datalog/conformance.sh` → **256/256 across 11 suites**
 (tokenize, parse, unify, eval, builtins, semi_naive, negation, aggregates,
 api, magic, demo). Source is ~3100 LOC, tests ~2900 LOC, public API
 documented in `lib/datalog/datalog.sx`.
@@ -320,6 +320,21 @@ large graphs.
 
 _Newest first._
 
+- 2026-05-10 — Bug-hunt round on parser/safety surfaced 7 real
+  bugs, each fixed with regression tests:
+  - Reserved relation names (`not`, `count`, `<`, `is`, ...) were
+    accepted as rule/fact heads — would silently shadow built-ins.
+  - Negative number literals (`n(-1).`) failed to parse — users
+    had to express them as `(- 0 1)` or via `is`.
+  - Unterminated block comment `/* ...` silently consumed the
+    rest of the input. Now raises with the position.
+  - Same silent-consume bug in unterminated string / quoted-atom.
+  - Empty-list rule head and non-list rule body weren't validated;
+    they'd crash later in `rest`. dl-add-rule! now checks shape.
+  - dl-magic-query with non-list / non-dict goal crashed cryptically.
+  - Tokenizer silently swallowed unrecognised characters (`?`, `!`,
+    `#`, `@`, etc.) — typos produced confusing downstream errors.
+
 - 2026-05-08 — Phase 6 driver: `dl-magic-query db query-goal`.
   Builds a fresh internal db from the caller's EDB + magic seed +
   rewritten rules, saturates, queries, returns substitutions —