## Summary
Follow-up draft PR for the CodeRabbit issues created from the #12999
review. This keeps the original stabilization PR merged as-is and moves
the non-functional TemplateHelper cleanup into its own small branch.
## Changes
- Extracted TemplateHelper route patterns into named module-scope
constants.
- Normalized the TemplateHelper route patterns to anchored regexes with
optional query-string handling.
- Extracted `mockCustomTemplates()` from `mockIndex()` and made `mock()`
register custom templates, core index, and thumbnails together.
- Added a private `registerRoute()` helper so every mocked route is
registered for teardown consistently.
- Simplified the fixed empty custom-template response to `body: '{}'`.
- Updated the cloud template filtering spec to use `templateApi.mock()`
instead of manually combining thumbnail and index mocks.
## Issues
- Closes#13014
- Closes#13016
- Closes#13017
- Closes#13018
- Related #13015: this PR normalizes the TemplateHelper route patterns
only. The broader fixture-wide route pattern convention cleanup remains
intentionally separate.
## Validation
- `pnpm exec oxfmt --check
browser_tests/fixtures/helpers/TemplateHelper.ts
browser_tests/tests/templateFilteringCount.spec.ts`
- `pnpm exec eslint browser_tests/fixtures/helpers/TemplateHelper.ts
browser_tests/tests/templateFilteringCount.spec.ts`
- `pnpm typecheck:browser`
- Pre-commit hook also ran `oxfmt`, `oxlint`, `eslint`, `pnpm
typecheck`, and `pnpm typecheck:browser` successfully.
Note: I attempted the targeted cloud Playwright spec locally with
`PLAYWRIGHT_LOCAL=1 PLAYWRIGHT_TEST_URL=http://localhost:5173 pnpm exec
playwright test browser_tests/tests/templateFilteringCount.spec.ts
--project=cloud`, but the local 5173 app was not running with the cloud
distribution configuration, so the distribution-filter assertions failed
in the expected local/cloud mismatch way. This should be verified by
CI's cloud project.
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