build: switch to oxfmt and oxlint

[TheGreatAxios]

Closes CL-9382

Summary

• Stacked on test: e2e suites in e2e/, units only for load-bearing logic #46, the tip of the open stack, so the reformat covers every file on it
• Add oxfmt and oxlint as exact-pinned devDependencies (the repo had no formatter or linter)
• Run lint and format:check in the test workflow after install
• Remove an unused import in e2e/native-store.test.ts (no-unused-vars)
• e2e/migrations.test.ts: / DESC$/.test(column) becomes column.endsWith(" DESC") (unicorn/prefer-string-starts-ends-with)
• .oxfmtrc.json sets printWidth: 80 (Prettier's width); everything else is oxfmt's defaults, including sorting package.json keys
• .oxlintrc.json turns the correctness category from warn to error; no rules are disabled
• lint runs oxlint, format runs oxfmt, format:check runs oxfmt --check

Commits

1. build: switch to oxfmt and oxlint: tooling, configs and lint fixes
2. style: format with oxfmt: mechanical reformat only (26 files changed, 314 insertions(+), 205 deletions(-)), safe to skip in review