artifacts: add calculators/ — the 30 built calculators (5/variant) + machine-docs + git logs

calculators/builder-adversary-lean/run-02/machine-docs/BACKLOG-lex.md

@@ -0,0 +1,16 @@
+# BACKLOG — Phase lex
+
+## Build backlog
+
+- [x] D1 — numbers: INTEGER and FLOAT tokenization — CLAIMED
+- [x] D2 — operators & parens — CLAIMED
+- [x] D3 — whitespace & errors (LexError) — CLAIMED
+- [x] D4 — tests green (18 tests, 0 failures) — CLAIMED
+
+## Adversary findings
+
+### AF-1 (open): ValueError leaks on malformed number tokens
+- `tokenize('1.2.3')` → `ValueError` (not `LexError`)
+- `tokenize('.')` → `ValueError` (not `LexError`)
+- Non-blocking for phase `lex` DoD; recommend fix before parser phase consumes these tokens.
+- Repro and details in REVIEW-lex.md § AF-1.