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

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

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+# JOURNAL-lex
+
+## Implementation notes
+
+Built `calc/lexer.py` with:
+- `Token` dataclass with `kind: str` and `value: Union[int, float, None]`
+- `LexError(Exception)` for invalid characters
+- `tokenize(src: str) -> list[Token]` scanning character by character
+
+Number scanning handles all three forms: integer (`42`), standard float (`3.14`), leading-dot float (`.5`), and trailing-dot float (`10.`). The key invariant: when `ch` is `.` we only enter number scanning if the next char is also a digit (to avoid confusing `.` used as an operator in other contexts). Trailing dot (`10.`) is handled because after scanning digits we check if the next char is `.` and absorb it into a float.
+
+14 tests written covering D1-D4 plus edge cases.