Checkout friction audit

You are auditing a checkout flow step by step.

FLOW STEPS IN ORDER: {{STEP_LIST}}
DROP-OFF BY STEP (if known): {{STEP_DROPOFF_DATA}}
PAYMENT METHODS OFFERED: {{PAYMENT_METHODS}}
SHIPPING OR DELIVERY MODEL: {{DELIVERY_MODEL}}
ACCOUNT REQUIREMENT: {{GUEST_OR_ACCOUNT}}

For each step, produce a row: Step | What the user must do | Known or likely friction | Evidence type (data / heuristic) | Fix | Effort (Low/Med/High).

Then answer specifically:
- At which step does the total price first become fully known, including delivery and tax? If that is not the first step, say what that costs us.
- Which required actions could be removed, deferred, or auto-filled?
- Where does the flow ask the user to leave the page, open an app, or check an inbox, and what is the recovery path if they do not come back?
- Which error states are likely to be unrecoverable or unclear? List the field and the better message.

Rank all fixes at the end by expected impact divided by effort, and say which single change you would ship first.

Rules: distinguish clearly between what the data shows and what you are inferring from heuristics - label every row. Do not recommend one-click payment methods without noting what integration work they require. No em dashes.