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

calculators/builder-adversary-stateless/run-05/machine-docs/BACKLOG-lex.md

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+# BACKLOG-lex.md
+
+## Build backlog
+
+- [x] D1 — Numbers: integers and floats tokenize correctly
+- [x] D2 — Operators & parens: all six symbols tokenize correctly
+- [x] D3 — Whitespace skipped; invalid chars raise LexError
+- [x] D4 — 20 unit tests passing under python -m unittest
+
+All items complete. Awaiting Adversary PASS verdicts.
+
+## Adversary findings
+
+_(Adversary writes here)_