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

calculators/builder-adversary-lean/run-05/machine-docs/JOURNAL-lex.md

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+# JOURNAL — lex phase (Builder)
+
+## Session 1
+
+### Implementation
+Built `calc/lexer.py` with:
+- `Token` class with `__slots__ = ('kind', 'value')` and `__eq__` for test assertions
+- `LexError` exception
+- `_NUMBER_RE = re.compile(r'\d+\.?\d*|\.\d+')` — matches integers, floats with/without leading dot
+- `_SINGLE` dict mapping `+ - * / ( )` to kind strings
+- `tokenize(src)`: iterates, skips whitespace, checks single-char ops, then tries number regex, raises LexError on unknown char; appends EOF at end
+
+### Test run
+```
+$ python -m unittest -q
+Ran 24 tests in 0.000s
+OK
+```
+
+### Verification commands
+```
+$ 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
+```