Batch translations during model hydration

[samuelpatro]

Fetching translatable models in a non-default locale runs one translation query per row during afterFetch. This preloads the active locale's translations for the rows being hydrated, in chunks of 500 ids, and gives each model its rows before fetched fires, so fetched listeners still see translated values. Fetching 100 records goes from 101 queries to 2.

Missing translations, the default locale, eager-loaded translations, dirty tracking and saves behave as before. Models that override loadTranslatableData() or getTranslateAttributeTable(), or whose morph class depends on the row, keep loading per row, since those can read other storage. cursor() is unchanged. Rows selected without their key also skip the translation query they used to run.

[samuelpatro]

Recheck of head 3c60da88 found an uncovered model override regression.

[P2] Allow replacement translation loaders to bypass the default store. hydrateWithTranslatableBatch() queries getTranslateAttributeTable() before a custom loadTranslatableData($locale) can run. A model whose loader supplies translations entirely from JSON/an external service, without calling parent, need not have the standard translation table.

Reproduced on PHP 8.4 with such a loader and no translate_attributes table: merge-base cursor() and get() both return the translated value; this PR's cursor() works but get() throws SQLSTATE[HY000]: General error: 1 no such table: translate_attributes from the preload query. The new override test decorates the parent loader and misses replacement storage.

Preserve this extension behavior with an override-aware fallback or overridable batch eligibility/storage, and add a regression without the default translation table. This contradicts the promised preservation of normal model overrides. The existing full suite passes (251 tests, 1529 assertions, one pre-existing risky test), so this needs additional coverage.

Separately, current develop has an add/add conflict in tests/Database/Traits/TranslatableTest.php; retain both sets of tests when updating.

[daftspunk]

Need to resolve conflicts

[samuelpatro]

@daftspunk rechecked and simplified this. Models that override loadTranslatableData() or getTranslateAttributeTable() already skip batching, so the preloaded rows no longer need to go through the loader. Model::newFromBuilder() now makes one applyTranslatableBatch() call that gives each model its rows before fetched. That removes the per-instance snapshot, the connection and table checks, and the newFromBuilderInstance() split. A model whose getMorphClass() depends on the row still loads per row. The test file went from 23 tests to 15, and each one fails when the behavior it covers breaks, including querying the wrong morph class or connection.

get() in a non-default locale (SQLite in memory, PHP 8.4, median of 15 runs):

Rows	develop	this PR
25	26 queries, 1.04 ms	2 queries, 0.31 ms
100	101 queries, 4.11 ms	2 queries, 1.09 ms
1000	1001 queries, 40.1 ms	3 queries, 12.4 ms

The default locale still runs one query and takes the same time (6.3 to 7.1 ms for 1000 rows on both). On MySQL or Postgres each skipped query also saves a network round trip, so the gap is larger than shown here.

Ready for another pass.

[daftspunk]

Bravo! Thanks