Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In `@packages/core/cairo_alpha/src/erc20.ts`:
- Around line 397-409: The override created when overridesMax is true for
flashMintConfigTrait::max_flash_loan ignores total_supply and can return a cap
larger than the remaining mint headroom; modify the function body (the fn
created for name 'max_flash_loan') to compute the remaining headroom as
u256::MAX - total_supply and return the minimum of customMax and that remaining
headroom (while still returning 0 if token != get_contract_address()); ensure
u256 arithmetic/underflow is handled correctly so you clamp to remaining =
u256::MAX - total_supply and return min(customMax, remaining).
- Around line 329-349: The parseFlashMintFeePercent function can produce an
arbitrarily large decimalScale/denominator (from decimalDigits) which may
overflow the u256 used later; add a guard after computing
decimalDigits/decimalScale that ensures decimalScale and the resulting
denominator (100n * decimalScale) fit within the u256 limit and reject inputs
with too many fractional digits by throwing OptionsError; specifically check
decimalScale <= MAX_DECIMAL_SCALE (or denominator <= MAX_U256 where MAX_U256 =
2n ** 256n - 1n) and reference the symbols decimalDigits, decimalScale,
denominator, and OptionsError in the check.
- Around line 319-326: The parseFlashMintMaxAmount path currently returns any
BigInt size and can emit out-of-range Cairo literals; modify
parseFlashMintMaxAmount to mirror premint's validation by converting the
computed BigInt (from getInitialSupply(value, Number(decimals))) through
toUint(..., 'u256') and return that value, and if toUint throws/returns an
error, surface it as an OptionsError for flashMintMaxAmount; keep the existing
checks for value === 'max' (return null) and the premintPattern/empty-string
validation that throws OptionsError.

---

Nitpick comments:
In `@packages/core/cairo_alpha/src/tests/with_components_off/erc20/erc20.test.ts`:
- Around line 125-173: Add two regression tests in the same suite that call
buildERC20 to assert validation failures for numeric-but-unrepresentable inputs:
one that sets flashMintMaxAmount to a numeric string greater than u256::MAX
(expecting the same OptionsError.messages.flashMintMaxAmount = 'Must be "max" or
a non-negative number'), and another that sets flashMintFeeMode: 'percent' with
flashMintFeePercent as a highly precise fractional string (many fractional
digits) that would overflow the denominator used to emit a Cairo literal
(expecting OptionsError.messages.flashMintFeePercent = 'Must be a number between
0 and 100'); mirror the existing test structure and assertions around buildERC20
to ensure these failure paths are covered.

In `@packages/ui/src/cairo_alpha/ERC20Controls.svelte`:
- Around line 38-42: The initialization can assign undefined to lastCustomMax if
opts.flashMintMaxAmount is undefined; change the initialization and the reactive
update to defensively default undefined to a safe string (e.g., '0') and coerce
any non-'max' value to String so lastCustomMax is always a string; update
references to the symbols lastCustomMax and opts.flashMintMaxAmount (both in the
initial let and the $: reactive block) to perform an explicit undefined check
and String(...) conversion instead of only comparing to 'max'.