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

calculators/builder-adversary-lean/run-01/machine-docs/JOURNAL-eval.md

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+# JOURNAL — Phase eval (Builder)
+
+## 2026-06-15 — Implementation
+
+Built evaluator, CLI, and test suite in one pass.
+
+AST walk in `calc/evaluator.py`:
+- `Num`: return `node.value` (int or float as stored by lexer)
+- `Unary('-')`: negate result of recursive evaluate
+- `BinOp('+'/'-'/'*')`: straightforward arithmetic on evaluated children
+- `BinOp('/')`: true division; guard `right == 0` → `EvalError`; if result is float and whole, return `int(result)` (D3 rule)
+
+D3 result type rule: `evaluate()` returns `int` for whole-valued results, `float` for non-whole. This means `4/2` → `int(2)` (prints `2`), `7/2` → `float(3.5)` (prints `3.5`). Pure integer arithmetic stays int throughout (Python int + int = int).
+
+CLI `calc.py`: catches `LexError`, `ParseError`, `EvalError` → stderr + exit 1. No traceback exposed.
+
+Test run: 46 tests pass (15 lexer + 20 parser + 11 evaluator). No regressions.
+
+Verified all plan cases:
+```
+python calc.py "2+3*4"   → 14
+python calc.py "(2+3)*4" → 20
+python calc.py "7/2"     → 3.5
+python calc.py "4/2"     → 2
+python calc.py "1/0"     → error to stderr, exit 1
+python calc.py "1 +"     → error to stderr, exit 1
+```