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

calculators/builder-adversary-stateless/run-02/machine-docs/JOURNAL-lex.md

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+# JOURNAL — Phase `lex`
+
+## Implementation notes
+
+### Design choices
+- Used `@dataclass` for `Token` to get `__eq__` and `__repr__` for free — useful in tests.
+- Number parsing: scan while char is digit or `.`; if `.` in raw string → `float()`, else `int()`. Handles `42`, `3.14`, `.5`, `10.`.
+- Single-char operators: dict lookup for O(1) dispatch.
+- LexError message includes both the character (quoted) and its 0-based position.
+
+### Test run (verified locally)
+```
+$ python -m unittest -q
+Ran 14 tests in 0.000s
+OK
+
+$ python -c "from calc.lexer import tokenize; print([(t.kind,t.value) for t in tokenize('3.5*(1-2)')])"
+[('NUMBER', 3.5), ('STAR', '*'), ('LPAREN', '('), ('NUMBER', 1), ('MINUS', '-'), ('NUMBER', 2), ('RPAREN', ')'), ('EOF', None)]
+
+$ python -c "from calc.lexer import tokenize; tokenize('1 @ 2')"
+Traceback (most recent call last):
+  ...
+calc.lexer.LexError: unexpected character '@' at position 2
+```