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

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

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+# BACKLOG-lex
+
+## Build backlog
+(Builder-owned — read-only to Adversary)
+
+## Adversary findings
+
+### AF-01: unhandled ValueError for malformed number literals [informational, non-blocking]
+
+**Repro:**
+```python
+from calc.lexer import tokenize, LexError
+tokenize('1.2.3')   # raises ValueError, not LexError
+tokenize('.')        # raises ValueError, not LexError
+tokenize('..')       # raises ValueError, not LexError
+```
+
+**Root cause:** `lexer.py` line 39: `float(raw)` is called without a try/except. If the
+greedy digit/dot scan produces an unparseable string (e.g. `1.2.3` or bare `.`), Python
+raises `ValueError` instead of the module's `LexError`.
+
+**Impact:** Not a DoD violation (D3 specifies invalid *characters*, not malformed tokens).
+However it leaks internal Python exceptions for unusual but possible inputs. Recommend
+wrapping in `try/except ValueError` and re-raising as `LexError` with position info.
+
+**Status:** Informational — Builder may address in this phase or a follow-up. Adversary
+will close this finding if re-tested and passing.