feat(editor): add SQL language support

[amaralkaff]

What

Adds CodeMirror SQL language support so .sql files (and common dialect extensions) get syntax highlighting in the editor.

Why

SQL files currently render as plain text. Mirrors the pattern from #127 (Go support).

How

• package.json: add @codemirror/lang-sql (~30 KB gzipped, ships all dialects)
• src/modules/editor/lib/languageResolver.ts: add loaders for sql (StandardSQL), psql/pgsql (PostgreSQL), mysql (MySQL), sqlite (SQLite). One package, dialect picked per extension.

Testing

• pnpm exec tsc --noEmit clean
• Manual smoke-test of the affected feature
• (If you touched src-tauri/) cargo check clean — N/A, no src-tauri/ changes; pnpm tauri dev builds clean
• (If UI) tested in pnpm tauri dev — opened .sql, .psql, .mysql, .sqlite files; keywords/strings/comments highlight per dialect

Screenshots / GIFs

N/A — pure language pack registration, no visual UI change beyond editor token colors.

Notes for reviewer

Same shape as #127. Bundle impact is one dynamic-imported chunk that only loads when a matching file is opened.

[crynta]

Thanks for the PR. Ended up going with @codemirror/legacy-modes/mode/sql instead in ee1c9bb (already bundled for Ruby/C/etc, ~20KB smaller, covers more dialects: standardSQL, mySQL, pgSQL, sqlite, mariaDB, msSQL, plSQL). No autocomplete from the parser-based lang-sql, but we don't have LSP anyway so visual highlighting is identical. Appreciate the push to add SQL support.