feat(cketh): expose per-token minimum deposit amounts in MinterInfo

[gregorydemay]

Balance-scan filter 1 only treats a deposit address as a scan candidate once its balance reaches a per-token minimum, so a smaller deposit is silently never detected and never credited. For the CEX deposit flow that threshold was invisible: a user could send a small amount to their deposit address, see nothing happen, and have no way to find out why.

get_minter_info now reports minimum_deposit_amounts — the minimum for each supported ckERC20 token, in that token's own units — so users and frontends can show the threshold alongside the deposit address. It is null while the ckERC20 feature is inactive, matching the existing per-token fields.

The thresholds are still the hard-coded rate snapshot; they will start tracking live prices once DEFI-2961's daily exchange-rate refresh lands, and this endpoint will reflect that automatically.

🤖 Generated with Claude Code

[zeropath-ai]

✅ No security or compliance issues detected. Reviewed everything up to 42be041.

Security Overview

• 🔎 Scanned files: 6 changed file(s)
• 🔗 Scan Link: https://zeropath.com/app/repositories/783a9bd4-fb4e-4e10-ab3c-c2fb2ddfb92f?scanId=fad747fc-83eb-411f-b941-fbcff75bd301&codeScanTypes=PrScan&tab=issues

Detected Code Changes

Change Type

Relevant files

Enhancement

► rs/ethereum/cketh/minter/src/balance_scan/mod.rs      Minimum balance for token to count as a scan candidate; expose as public function ► rs/ethereum/cketh/minter/src/endpoints.rs      Add Erc20MinimumDeposit struct and integrate into MinterInfo ► rs/ethereum/cketh/minter/src/main.rs      Use min_deposit in get_minter_info ► rs/ethereum/cketh/minter/src/main.rs      Import min_deposit and balance_scan together ► rs/ethereum/cketh/minter/src/main.rs      Update get_minter_info to include minimum_deposit_amounts in response ► rs/ethereum/cketh/minter/tests/ckerc20.rs      Update tests to account for Erc20MinimumDeposit in MinterInfo ► rs/ethereum/cketh/minter/tests/cketh.rs      Adjust tests to reflect new minimum_deposit_amounts field in MinterInfo