feat: Sepolia card account end-to-end demo scripts (No Merge)

[livingrockrises]

Summary

Adds a full suite of Sepolia demo scripts covering the card account lifecycle using Startale smart accounts (ERC-7579) and the Rhinestone SDK.

All sepolia scripts run without a paymaster — the counterfactual smart account must be pre-funded with Sepolia ETH before running.

Scripts (run in order)

Scripts run without a paymaster — the counterfactual smart account must be pre-funded with Sepolia ETH before running.

Scripts (run in order)

Script	Account (index)	What it does
demo_basic_userop_without_pm.ts	index: 0	Deploys the ERC-7579 card controller smart account
demo_install_controller_validator.ts	index: 0	Installs ControllerValidator module on the card controller SA
demo_make_card_account.ts	index: 1	Calls CardAccountFactory.makeNewCardAccount via UserOp to deploy a card account clone

Scripts (run in order)

Script	Account (index)	What it does
demo_basic_userop_without_pm.ts	index: 0	Deploys the ERC-7579 card controller smart account
demo_install_controller_validator.ts	index: 0	Installs ControllerValidator module on the card controller SA
demo_make_card_account.ts	index: 1	Calls CardAccountFactory.makeNewCardAccount via UserOp to deploy a card account clone
demo_basic_userop_without_pm.ts	index: 0	Deploys the ERC-7579 card controller smart account
demo_install_controller_validator.ts	index: 0	Installs ControllerValidator module on the card controller SA
demo_make_card_account.ts	index: 1	Calls CardAccountFactory.makeNewCardAccount via UserOp to deploy a card account clone
demo_install_controller_validator.ts	index: 0	Installs ControllerValidator module on the card controller SA
demo_make_card_account.ts	index: 1	Calls CardAccountFactory.makeNewCardAccount via UserOp to deploy a card account clone
demo_deploy_nexus_with_controller_validator.ts	—	Alternative: deploy a Rhinestone Nexus account with ControllerValidator as the sole validator (useful for testing a new card account implementation)
demo_card_account_usdc_approval.ts	index: 1	Grants unlimited USDSC approval from the user's SA to the card account
demo_card_account_usdc_approval.ts	index: 1	Grants unlimited USDSC approval from the user's SA to the card account
demo_deposit_from_user_account.ts	index: 0	Card controller calls depositFromUserAccount on the card account — pulls USDSC from user SA into card account (default: 500 USDSC)
demo_settle_card_balance.ts	index: 0	Card controller calls settleCardBalance — sends USDSC from card account to Startale treasury

Key addresses (Sepolia)

• USDSC: 0x7E426d026f604d1c47b50059752122d8ab1E2C28
• Startale settle target: 0x22C9Baf7A0db2190AD74fCE24faBD68Ec6F97DAc

Required env vars

SEPOLIA_BUNDLER_URL=
OWNER_PRIVATE_KEY=
CONTROLLER_VALIDATOR_ADDRESS=
CARD_ACCOUNT_FACTORY_ADDRESS=
CARD_ACCOUNT_ADDRESS= # set after running demo_make_card_account

|--------|----------------|--------------|
| demo_make_card_account.ts | index: 1 | Calls CardAccountFactory.makeNewCardAccount via UserOp to deploy a card account clone |

| demo_deploy_nexus_with_controller_validator.ts | — | Alternative: deploy a Rhinestone Nexus account with ControllerValidator as the sole validator (useful for testing a new card account implementation) |

| demo_card_account_usdc_approval.ts | index: 1 | Grants unlimited USDSC approval from the user's SA to the card account |

| demo_deposit_from_user_account.ts | index: 0 | Card controller calls depositFromUserAccount on the card account — pulls USDSC from user SA into card account (default: 500 USDSC) |

| demo_settle_card_balance.ts | index: 0 | Card controller calls settleCardBalance — sends USDSC from card account to Startale treasury (default: 10 USDSC) |

Key addresses (Sepolia)

• USDSC: 0x7E426d026f604d1c47b50059752122d8ab1E2C28 (named USDR on Sepolia)
• Startale settle target: 0x22C9Baf7A0db2190AD74fCE24faBD68Ec6F97DAc

Required env vars

SEPOLIA_BUNDLER_URL=
OWNER_PRIVATE_KEY=
CONTROLLER_VALIDATOR_ADDRESS=
CARD_ACCOUNT_FACTORY_ADDRESS=
CARD_ACCOUNT_ADDRESS= # set after running demo_make_card_account
RHINESTONE_API_KEY= # only needed for demo_deploy_nexus_with_controller_validator

Test plan

• demo_make_card_account — card account deployed at 0xBf0136996da3165d252a60471e7b6CbDB9153928
• demo_card_account_usdc_approval — unlimited USDSC approval set (tx 0xd4256d...)
• demo_deposit_from_user_account — 500 USDSC deposited into card account (tx 0x976f9a...)
• demo_settle_card_balance — 10 USDSC settled to Startale treasury (tx 0x33703e...)

[livingrockrises]

• Adds two end-to-end card account demo flows on Sepolia, organised under
  src/sepolia/startale-card-controller/ and src/sepolia/rhinestone-card-controller/
• Flow 1 (Startale): Startale AA (index 0) as card controller, Startale bundler —
  covers install ControllerValidator, activate card account (makeNewCardAccount + USDSC
  approve in one UserOp), depositFromUserAccount, settleCardBalance
• Flow 2 (Rhinestone): Rhinestone Nexus with ControllerValidator module as card
  controller, Pimlico bundler — covers deploy Nexus, smoke-test UserOp, activate card
  account, depositFromUserAccount, settleCardBalance via account.sendUserOperation
• Adds src/sepolia/README.md with run order, explanation of each script, and env var
  reference table
• Adds NEXUS_CARD_ACCOUNT_ADDRESS to .env_template

Key implementation notes

• Rhinestone deploy uses bundler.type: 'custom' pointing to Pimlico to force
  deployWithBundler path (avoids Rhinestone orchestrator which requires a Rhinestone
  API key); the sepoliaWithMinFees chain override sets maxPriorityFeePerGas: 2 gwei
  to meet Pimlico's minimum
• Rhinestone sendUserOperation scripts use bundler.type: 'pimlico' so the SDK calls
  pimlico_getUserOperationGasPrice for correct fee estimation (the chain override does
  not intercept bundler-level fee estimation)
• Card account activation for Flow 2 uses Startale AA index 3 (fresh account) to avoid
  the factory's one-card-account-per-user restriction

Test runs (Sepolia)

• Nexus deployed at 0xB892b0f7419Ed7eCA94f02AaAA241D85D747f84E
• Flow 2 deposit: confirmed via UserOp
• Flow 2 settle: confirmed via UserOp