refactor(api): migrate console conversation variables response model to BaseModel

[ai-hpc]

Part of #28015

Summary

Extract Flask-RESTX response model usage in api/controllers/console/app/conversation_variables.py into Pydantic ResponseModel classes and register them with register_schema_models(). Remove @marshal_with and inline console_ns.model(...) response model assembly for conversation variable pagination responses.

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 and make type-check (backend) and cd web && pnpm exec vp staged (frontend) to appease the lint gods

[github-actions]

Pyrefly Diff

No changes detected.

[Copilot]

Pull request overview

Refactors the console conversation variables GET endpoint to replace Flask-RESTX response marshalling/models with Pydantic ResponseModel classes registered via register_schema_models().

Changes:

• Introduces ConversationVariableResponse and PaginatedConversationVariableResponse Pydantic models and registers them for Swagger.
• Removes @marshal_with and inline console_ns.model(...) assembly, returning model_dump(mode="json") instead.
• Adds unit tests for the conversation variables API response shape and query validation.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.

File	Description
api/controllers/console/app/conversation_variables.py	Migrates response modeling/marshalling to Pydantic ResponseModel + schema registration and returns JSON via model_dump.
api/tests/unit_tests/controllers/console/app/test_conversation_variables_api.py	Adds unit tests covering paginated response structure and missing conversation_id validation.

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[github-actions]

Pyrefly Diff

base → PR

--- /tmp/pyrefly_base.txt	2026-04-14 18:16:41.177957338 +0000
+++ /tmp/pyrefly_pr.txt	2026-04-14 18:16:30.954838437 +0000
@@ -1,5 +1,7 @@
 ERROR Object of class `App` has no attribute `access_mode` [missing-attribute]
    --> controllers/console/app/app.py:561:13
+ERROR Object of class `object` has no attribute `value` [missing-attribute]
+  --> controllers/console/app/conversation_variables.py:48:24
 ERROR Argument `str | None` is not assignable to parameter `language` with type `str` in function `services.account_service.AccountService.send_email_register_email` [bad-argument-type]
   --> controllers/console/auth/email_register.py:75:108
 ERROR Object of class `MissingRouter` has no attribute `get` [missing-attribute]