test(auth): add sign-in smoke test and core validation

[Jingyi-Dify]

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Summary

What

• Add e2e/features/auth/sign-in.feature with a happy-path sign-in scenario tagged @smoke @core @unauthenticated
• Add e2e/features/step-definitions/auth/sign-in.steps.ts with three step definitions: open sign-in page, submit credentials, assert landing on apps console
• Add @core tag to create-app.feature and sign-out.feature; add @core @mode-matrix to create-chatbot-app.feature and create-workflow-app.feature

Why

The existing E2E suite covered sign-out and unauthenticated redirect but had no explicit sign-in scenario. Every authenticated scenario implicitly depends on sign-in working, but it was never directly
tested. The tag additions align existing scenarios with the planned @smoke / @core / @mode-matrix suite structure for CI-level targeted runs.

Effect

• --tags @smoke now includes a sign-in scenario that runs on every PR
• Step definitions reuse adminCredentials from fixtures/auth.ts and existing locator patterns — no new infrastructure required
• Pre-existing lint errors in unrelated e2e files are not introduced or worsened by this change

Screenshots

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Checklist

• This change requires a documentation update, included: Dify Document
• I understand that this PR may be closed in case there was no previous discussion or issues. (This doesn't apply to typos!)
• I've added a test for each change that was introduced, and I tried as much as possible to make a single atomic change.
• I've updated the documentation accordingly.
• I ran make lint && make type-check (backend) and cd web && pnpm exec vp staged (frontend) to appease the lint gods

[Copilot]

Pull request overview

Adds a dedicated happy-path sign-in E2E smoke scenario and aligns existing E2E scenarios with the @core / @mode-matrix tagging scheme for targeted CI runs.

Changes:

• Add a new @smoke @core @unauthenticated sign-in feature plus step definitions that perform login and assert landing on /apps.
• Tag existing app-creation and sign-out features with @core (and @mode-matrix where applicable) to support suite partitioning.

Reviewed changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
e2e/features/step-definitions/auth/sign-in.steps.ts	Adds Playwright+Cucumber steps to navigate to /signin, submit admin credentials, and assert URL is /apps.
e2e/features/auth/sign-in.feature	Introduces the new sign-in smoke scenario tagged for CI selection.
e2e/features/auth/sign-out.feature	Adds @core tag to include sign-out coverage in the core suite.
e2e/features/apps/create-app.feature	Adds @core tag for core suite coverage.
e2e/features/apps/create-chatbot-app.feature	Adds @core @mode-matrix tags for matrixed runs.
e2e/features/apps/create-workflow-app.feature	Adds @core @mode-matrix tags for matrixed runs.

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[lyzno1]

Related #34278