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

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

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+# JOURNAL — phase `lex`
+
+## Implementation
+
+Built `calc/lexer.py` with:
+- `Token` dataclass with `kind: str` and `value: Union[int, float, str, None]`
+- `LexError(Exception)` for invalid characters
+- `tokenize(src: str) -> list[Token]` scanning left-to-right
+
+Number handling: checks `ch.isdigit()` OR `ch == '.' followed by digit` (for `.5` case).
+Collects integer digits, then optionally a `.` and fractional digits.
+Result is `int` if no `.` seen, `float` otherwise — handles `10.` (trailing dot) correctly.
+
+Operators: simple char-dispatch to the 6 operator/paren token kinds.
+
+Whitespace: space and tab explicitly skipped via `continue`.
+
+Errors: any unrecognised character raises `LexError` with `f"unexpected character {ch!r} at position {i}"`.
+
+EOF appended unconditionally as the final token.
+
+## Test run
+
+```
+$ python -m unittest -q
+......................
+Ran 21 tests in 0.000s
+
+OK
+```
+
+## Verification
+
+```
+$ 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
+```