test: migrate browser_tests/ to @e2e/ path alias and add lint rule (#10958)

## Summary

Complete the @e2e/ path alias migration started in #10735 by converting
all 354 remaining relative imports and adding a lint rule to prevent
backsliding.

## Changes

- **What**: Migrate all relative imports in browser_tests/ to use
`@e2e/` (intra-directory) and `@/` (src/ imports) path aliases. Add
`no-restricted-imports` ESLint rule banning `./` and `../` imports in
`browser_tests/**/*.ts`. Suppress pre-existing oxlint `no-eval` and
`no-console` warnings exposed by touching those files.

## Review Focus

- ESLint flat-config merging: the `@playwright/test` ban and
relative-import ban are in two separate blocks to avoid last-match-wins
collision with the `useI18n`/`useVirtualList` blocks higher in the
config.
- The `['./**', '../**']` glob patterns (not `['./*', '../*']`) are
needed to catch multi-level relative paths like `../../../src/foo`.

Follows up on #10735

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-10958-test-migrate-browser_tests-to-e2e-path-alias-and-add-lint-rule-33c6d73d365081649d1be771eac986fd)
by [Unito](https://www.unito.io)

Co-authored-by: Amp <amp@ampcode.com>

browser_tests/fixtures/helpers/ModelLibraryHelper.ts

@@ -3,7 +3,7 @@ import type { Page, Route } from '@playwright/test'
 import type {
   ModelFile,
   ModelFolderInfo
-} from '../../../src/platform/assets/schemas/assetSchema'
+} from '@/platform/assets/schemas/assetSchema'
 
 const modelFoldersRoutePattern = /\/api\/experiment\/models$/
 const modelFilesRoutePattern = /\/api\/experiment\/models\/([^?]+)/