Complete Kernel-managed Visa card checkout in CLI

[hiroTamada]

summary

• support Kernel-managed wallet enrollment and card purchase requests, with Visa spend approval, token eligibility guidance, and the advertised browser fill flow
• add confirm_transaction through --params or --spec-file, validating required fields, enums, integer amounts, uppercase currency, RFC3339 timestamps, and unknown/duplicate properties before any request; send the exact JSON body without automatic retries
• allow only an explicitly advertised, parameterless restart_verification --open in recovery_required; hide and refuse all other operations even when advertised, retain the original refusal unless restart is advertised, and suppress stale recovery action URLs
• document three-field Kernel card fill, merchant-page billing entry, and reporting the observed checkout outcome once without inferring success from fill or retrying unknown outcomes
• merge main normally, retain its newer SDK/toolchain, preserve lowercase help/output, and reject card details including expiry inputs in Kernel wallet/card specs

compatibility

• restart_verification depends on kernel/kernel#4760, currently deployed only to staging; availability is always gated on available_operations
• the retained SDK does not yet generate confirm_transaction or restart_verification request types. confirmation uses option.WithRequestBody with validated JSON and option.WithMaxRetries(0); replace the raw body with the typed parameter once the SDK is regenerated. restart uses the existing advertised parameterless-operation path.

validation

• make test passed (go vet ./... and go test ./...)
• make lint completed successfully, but the repository's recipe masks lint failures: the full run reports 72 existing warnings (main reports 74); no unrelated lint cleanup included
• golangci-lint run --new-from-rev=origin/main passed with 0 issues
• make build and built-binary wallet/card/invoke --help checks passed
• mock HTTP coverage for confirmation bodies via params/file/stdin, all enum and amount boundaries, invalid-input rejection before any request, reporting availability after consumption, no automatic retries, advertised/unadvertised recovery restart, advertised authorize/fill/preparation refusal without a POST, recovery display filtering and conditional restart guidance, explicit --open, three-field Kernel fill, card-data rejection, and updated guidance/examples
• no live payment operations or real API resource mutations

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Note

High Risk
Changes payment credential flows, recovery behavior, and outcome reporting—mistakes could cause duplicate charges, wrong reconciliation, or unsafe handling of card data.

Overview
Adds Kernel-managed vault payments to the CLI: kernel wallets/cards, vaults wallets get, hosted enrollment, token-eligibility guidance, browser fill for ready Kernel cards (no stored billing; origin locked to merchant_url), and blocking card PAN/CVC/expiry in --spec.

Introduces confirm_transaction via --params / --spec-file with strict local validation and a raw JSON POST (no retries) until the SDK exposes the operation type.

Tightens recovery_required: only an advertised, parameterless restart_verification (optional --open) may run; other operations stay blocked with updated errors and human guidance. README and command help document the full Kernel checkout flow (authorize → fill → one-time outcome report).

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