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

calculators/builder-adversary-deferred/run-03/machine-docs/DECISIONS.md

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+# Decisions (append-only)
+
+## lex phase
+
+**Token.value type for operators:** stored as the literal character string (e.g. `'+'`). Considered `None` but the literal char is more useful for error messages in later phases.
+
+**Number parsing:** greedy scan of `[0-9.]` then classify by presence of `.`. A string like `1.2.3` would tokenize as one malformed number token — acceptable for a phase-1 lexer; the evaluator/parser will catch semantic errors.