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

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

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+# JOURNAL — eval phase
+
+## 2026-06-15 — Implementation
+
+Built evaluator, CLI, and tests in one go.
+
+### evaluator.py
+
+`evaluate(node)` walks the AST recursively:
+- `Num` → return `node.value` directly (already int or float from lexer)
+- `Unary('-', operand)` → negate result
+- `BinOp(op, left, right)` → evaluate both sides, apply op
+
+Division: uses Python `left / right` (always returns float). If `right == 0`, raises `EvalError("Division by zero")`.
+
+D3 result type rule: after computing a float result in BinOp, if `result == int(result)` we cast to int. This ensures `4/2 → 2` (int) and `7/2 → 3.5` (float). Integer arithmetic returns int naturally.
+
+### calc.py CLI
+
+`main()` accepts exactly one argv argument (the expression string).
+Catches `LexError`, `ParseError`, `EvalError` → prints `Error: <msg>` to stderr, exits 1.
+On success prints `result` (which is already int or float with correct type per D3 rule).
+
+### Test run output
+
+```
+$ python -m unittest -q
+Ran 62 tests in 0.001s
+OK
+```
+
+(45 prior tests from lex+parse phases, 17 new evaluator tests)
+
+### CLI checks
+
+```
+$ 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: Division by zero (exit 1)
+$ python calc.py "1 +"      → Error: Unexpected end of input (exit 1)
+```