feat(editor): show total row count for the current query

[Davydhh]

Summary

The result footer already had a # button that computes the exact row count on demand (an exact COUNT(*) is skipped by default because it's expensive on large tables). Until now that count only fed the "Page X of Y" page total. This PR surfaces the actual number — the # button resolves into 12,345 rows once loaded — and fixes two correctness bugs in the existing count along the way.

Changes

• Show the total count — after loading, the footer reads Page X of Y | 12,345 rows (the # button's slot becomes the count). New i18n key editor.rowCount, added to all 8 locales.
• Count now respects the filter (bug fix) — loadCount counted the base SELECT * FROM <table>, ignoring the WHERE typed in the filter box. It now counts the current table with the same filter (dropping ORDER BY/LIMIT, which are pointless for a count and would otherwise cap it).
• Count resets on query change (bug fix) — the count was preserved across any re-run, so a changed query showed a stale total. It's now preserved only across pagination of the same query and cleared when the query or filter changes.

How to test

1. Open a table (or run SELECT * FROM <table>).
2. Type a filter and run.
3. Click # → exact filtered count appears (e.g. 39,258 rows), matching SELECT count(*) FROM <table> WHERE <condition>.
4. Change the filter/query and re-run → count clears and # reappears; click it → the new, correct count shows.
5. Paginate → the count persists across pages.

Notes

• The count stays on-demand (the # button); the performance-motivated design of skipping COUNT(*) by default is unchanged.
• Frontend-only — no backend / count_query changes.