Prepares BlitzKit for tier XI tanks ahead of their release. Tier X was hardcoded as the maximum in the tank search filters, the guesser and the tech tree, and had no roman numeral beyond X.
- Added `XI` to `TIER_ROMAN_NUMERALS`
- Added an awaitable tier list derived from the highest tier in the tank definitions, so nothing changes until tier XI tanks exist
- Used it for the tank search tier filters and the guesser tier picker and defaults
- Made the tech tree check for successors instead of assuming tier X is the last tier
Fixes#302
**Enter key**
- Enter redirected to the previous results' first tank while a search was still buffering, because the key handler captured a stale `searching` value.
- Enter on an empty field redirected to the first tank of the unfiltered list (Sheridan).
- The handler now reads live filter state and only acts when there is a settled search, matching the quick-link button.
**Full names in search**
- Search only knew short tank names, so queries like "super pershing" found nothing when the game stores a short form.
- Add an optional `name_full` to `TankDefinition`, filled from the game's full name when a short name exists, and index it (plus an accent-stripped copy) in `fetchTankNames` / `SEARCH_KEYS`.
- Displayed names are unchanged. Full names become searchable once the definitions are regenerated on the next build.