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

calculators/builder-adversary-min/run-03/machine-docs/JOURNAL-parse.md

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+# JOURNAL — phase parse
+
+## Build notes
+
+Implemented a classic recursive-descent parser.
+
+Grammar (precedence lowest → highest):
+```
+expr   → term   (('+' | '-') term)*
+term   → unary  (('*' | '/') unary)*
+unary  → '-' unary | primary
+primary→ NUMBER | '(' expr ')'
+```
+
+The `while` loops in `_expr` and `_term` produce left-associative trees naturally: each iteration wraps the accumulated left subtree as the new `node`, so 8-3-2 folds as ((8-3)-2).
+
+Unary minus recurses right (`_unary` calls itself) to allow `--5` to parse as `Unary('-', Unary('-', Num(5)))`.
+
+Empty input is caught by checking for EOF before entering `_expr`. Trailing tokens (e.g. `1 2`) are caught by the EOF check after `_expr` returns. Unclosed parens are caught in `_primary` when expecting RPAREN but finding EOF.
+
+36 tests: 3 precision, 3 left-assoc, 3 paren, 4 unary, 5 error, plus 18 from lexer phase.