Post-migration hop lands on Google account chooser with signed-out row; CLI stalls instead of auto-selecting recorded account #763

Measured 2026-09-08 on profile presentation-reels-google. $0 (navigation + DOM reads only, Generate never clicked).

What happens

After the migration hop the bootstrap/mint path lands on one of:

• flow.google.com/about (public landing, no recaptcha script), or
• accounts.google.com/v3/signin/accountchooser with the recorded account row present but signed out.

The CLI has the recorded account in the profile's .gflow_account file, but nothing ever clicks the matching chooser row, so a later mint fails with RecaptchaError/1 behind an opaque UnexpectedError (exit 1).

Why it is wrong

A chooser stall is not a generic error and not selector drift: the account to select is already recorded locally. Retrying the same command replays the same stall. The failure should name the situation (recorded account not selectable) with a stable typed error + exit code so scripts can branch to gflow auth login instead of parsing stderr.

Proposed fix

• Auto-select the recorded account row on the chooser (match by .gflow_account email, case-insensitive) right after bootstrap goto, before any mint/probe work.
• New typed error for the unselectable cases (row absent, click-through does not return to editor/session page, --account mismatch): dedicated class + exit code, retryable=false, never UnexpectedError.
• gflow auth login --account <email> asserts recorded == verified email.

Related: #756 covers the /about landing misreported as UiSelectorDriftError; this issue covers the accountchooser landing. The two are sibling post-migration landing states.