i18n: data-i18n attributes and t() helper in pair/repair forms

Wire up the pair edit_configuration and repair_configuration HTML to
the locale system: data-i18n attributes on every static label, t() helper
inside the IIFE, applyTranslations() on Homey ready, and t()-driven
strings in all dynamically built HTML (anchor rows, profile editor,
device cards, lux/solar detail blocks, save button states, error alerts).

Solar event labels in the dropdown now resolve from
pair.circadian_light_group.solar_event_* keys, falling back to English
when a locale doesn't define them.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: Tiwas