Suggest ready-to-use VAT case / rate / account bundles for a booking line.

Turns a plain-language context — a purchase vs a sale — into ranked, copy-paste-ready VAT bundles. Each bundle carries the verbatim <code>vatCaseLink</code> and <code>vatRateLink</code> to drop into a booking line's <code>links</code>, plus a suggested <code>vatAccountCode</code>. Supply <code>amount</code> to also receive a net/VAT preview. The bundle marked <code>recommended</code> is the server's best guess.<br/><br/><strong>Rebuilding the Manual-booking VAT UI from this response (read this if you are generating a UI).</strong> This endpoint returns a <em>flat array</em>, but the Manual-booking screen renders it as <strong>three linked dropdowns plus two toggles and an auto-computed amount</strong>. Map each control as follows:<table border="1" cellpadding="4"><tr><th>GUI control</th><th>Driven by</th><th>How to build it</th></tr><tr><td><strong>VAT</strong> on/off toggle</td><td>client-side state (not in this response)</td><td>OFF → the line has no VAT: don't call this endpoint, add no VAT links/fields. ON → call this endpoint and show the dropdowns below.</td></tr><tr><td><strong>VAT case</strong> dropdown (e.g. "taxable supply")</td><td>distinct <code>vatCaseCode</code> (label it with <code>label</code>)</td><td>Group the array by <code>vatCaseCode</code>; one entry per distinct case.</td></tr><tr><td><strong>VAT rate</strong> dropdown (e.g. "8.1%")</td><td><code>vatRateDisplay</code></td><td>Cascades from the chosen case: the rows sharing the selected <code>vatCaseCode</code> are the rate options.</td></tr><tr><td><strong>VAT account</strong> dropdown (e.g. "1170 | Input tax VAT")</td><td><code>vatAccountCodes</code></td><td>List all <code>vatAccountCodes</code>; preselect <code>vatAccountCode</code>.</td></tr><tr><td><strong>including / excluding</strong> toggle</td><td>the <code>amountKind</code> query param</td><td><code>including</code> = <code>GROSS_INCLUSIVE</code>; <code>excluding</code> = <code>NET_EXCLUSIVE</code>. Flipping it means re-calling this endpoint to refresh the preview.</td></tr><tr><td>Debit / Credit amount preview</td><td><code>previewNet</code> / <code>previewVat</code></td><td>Null until you pass <code>amount</code>. Re-call with the new <code>amount</code>/<code>amountKind</code> to refresh.</td></tr></table><strong>End-to-end recipe (call → render → book):</strong><ol><li>User turns the VAT toggle ON. Call this endpoint with <code>direction</code> (PURCHASE/SALE), the line's <code>accountCode</code>, the user's <code>amount</code>, the <code>amountKind</code> from the including/excluding toggle, and the <code>date</code> you will book on.</li><li>Render the dropdowns per the table above; preselect the row where <code>recommended = true</code>.</li><li>When the user picks a row, send it to <code>POST /core/v1/bookings?autoCalculateVat=true</code>: on the VAT-bearing line set <code>links = "<vatCaseLink>,<vatRateLink>"</code> (both verbatim), <code>vatAccountCode = <vatAccountCode></code>, your <code>amount</code>, and <code>isExcludeVatAmount</code> matching the <code>amountKind</code> you queried — then omit the VAT counterpart line; the server generates it (matching <code>previewNet</code>/<code>previewVat</code>). Pass the same <code>date</code> you will book on.<br/><br/><strong>Coverage:</strong> the response mirrors the booking GUI's two dropdowns. The VAT-case list is direction-agnostic (every configured case is offered regardless of <code>direction</code>), and the rate list includes every configured version of each rate code the case references — current <em>and</em> historical — so a line dated before a rate change still finds its rate.