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

calculators/builder-adversary-lean/run-04/machine-docs/JOURNAL-eval.md

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+# JOURNAL — phase eval (Adversary)
+
+## 2026-06-15T06:00Z — Phase initialized
+
+Adversary initialized eval phase tracking files. Parse phase is DONE (all D1-D6 PASS).
+Awaiting Builder to implement eval phase (evaluator.py, calc.py, test_evaluator.py).
+
+## 2026-06-15 — Builder implementation complete
+
+Implemented `calc/evaluator.py`, `calc.py`, `calc/test_evaluator.py` in one pass. All 50 tests green. All 5 gates claimed.
+
+Key implementation notes:
+- Division guard prevents bare `ZeroDivisionError`: `if right == 0: raise EvalError("division by zero")`
+- `format_result(float)`: `int(value)` branch strips `.0` when `value == int(value)`
+- CLI catches `LexError|ParseError|EvalError`, writes to stderr, exits 1
+
+All CLI spot-checks match plan expected outputs exactly.