Request the numeric keyboard for digits-only postcode formats

[boo-code]

Questions	Answers
Description?	The postcode input renders with the default keyboard on touch devices even for countries whose zip format only allows digits (core format tokens: N = digit, L = letter, C = iso code — France, Germany, the US, Italy, Spain and most others are pure NNNNN), forcing a keyboard switch on every checkout. Keyboard optimization is one of the standard mobile checkout items (https://baymard.com/blog/mobile-checkout — 60% of top mobile sites fail at least 2 of 5 keyboard optimizations; the module already uses type="email" and type="tel"). This sets inputmode="numeric" on the postcode FormField via setAttr() when the country's zip_code_format matches ^N+$; formats with letters or separators keep the default keyboard, since the numeric layout could not type them. Rendering happens through the theme's form fields partial via the paired PrestaShop/hummingbird#1063 (core already exports FormField::attr in toArray() and runs the additionalHtmlAttributesFormFields hook, but the partial never rendered the slot); with an older theme the attribute is simply not rendered and the behavior stays as today.
Type?	improvement
BC breaks?	no
Deprecations?	no
Fixed ticket?
How to test?	vendor/bin/phpunit -c tests/php/phpunit.xml --filter AddressFieldsFormatTraitTest — asserts ['inputmode' => 'numeric'] for a NNNNN country and an empty attr map for a lettered (LN NL) and an empty format. With PrestaShop/hummingbird#1063 applied on a 9.2 shop, all four checkout postcode inputs (inline and modal, delivery and invoice) render inputmode="numeric" for France — verified live; a touch device opens the digit keyboard on the field.

[ps-jarvis]

Hello @boo-code!

This is your first pull request on ps_onepagecheckout repository of the PrestaShop project.

Thank you, and welcome to this Open Source community!