fix: hide soft-deleted conversations from console APIs

[csurong]

Summary

• exclude soft-deleted conversations from console conversation detail lookups
• prevent message history lookups from returning soft-deleted conversations
• add regression coverage for both console endpoints

Fixes #40976

Screenshots

Not applicable. This is a backend-only change.

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 vp staged (frontend) to appease the lint gods

Tests

• uv run --project api pytest -q api/tests/unit_tests/controllers/console/app/test_conversation_api.py api/tests/unit_tests/controllers/console/app/test_message_api.py
• uv run --project api ruff check api/controllers/console/app/conversation.py api/controllers/console/app/message.py api/tests/unit_tests/controllers/console/app/test_conversation_api.py api/tests/unit_tests/controllers/console/app/test_message_api.py
• uv run --project api ruff format --check api/controllers/console/app/conversation.py api/controllers/console/app/message.py api/tests/unit_tests/controllers/console/app/test_conversation_api.py api/tests/unit_tests/controllers/console/app/test_message_api.py

[github-actions]

Pyrefly Diff

base → PR

--- /tmp/pyrefly_base.txt	2026-08-20 02:14:00.777494061 +0000
+++ /tmp/pyrefly_pr.txt	2026-08-20 02:13:45.913384413 +0000
@@ -3375,13 +3375,13 @@
 ERROR Cannot index into `object` [bad-index]
    --> tests/unit_tests/controllers/console/app/test_audio.py:137:17
 ERROR Argument `SimpleNamespace` is not assignable to parameter `current_user` with type `Account` in function `controllers.console.app.message._update_message_feedback` [bad-argument-type]
-   --> tests/unit_tests/controllers/console/app/test_message_api.py:115:26
+   --> tests/unit_tests/controllers/console/app/test_message_api.py:127:26
 ERROR Argument `SimpleNamespace` is not assignable to parameter `app_model` with type `App` in function `controllers.console.app.message._update_message_feedback` [bad-argument-type]
-   --> tests/unit_tests/controllers/console/app/test_message_api.py:116:23
+   --> tests/unit_tests/controllers/console/app/test_message_api.py:128:23
 ERROR Argument `SimpleNamespace` is not assignable to parameter `app_model` with type `App` in function `controllers.console.app.message._get_message_detail` [bad-argument-type]
-   --> tests/unit_tests/controllers/console/app/test_message_api.py:138:19
+   --> tests/unit_tests/controllers/console/app/test_message_api.py:150:19
 ERROR Argument `Literal['550e8400-e29b-41d4-a716-446655440000']` is not assignable to parameter `message_id` with type `UUID` in function `controllers.console.app.message._get_message_detail` [bad-argument-type]
-   --> tests/unit_tests/controllers/console/app/test_message_api.py:139:20
+   --> tests/unit_tests/controllers/console/app/test_message_api.py:151:20
 ERROR Argument `list[FromClause]` is not assignable to parameter `tables` with type `Sequence[Table] | None` in function `sqlalchemy.sql.schema.MetaData.create_all` [bad-argument-type]
   --> tests/unit_tests/controllers/console/app/test_model_config_api.py:89:51
 ERROR Argument `str | None` is not assignable to parameter `s` with type `bytearray | bytes | str` in function `json.loads` [bad-argument-type]

[github-actions]

Pyrefly Type Coverage

Metric	Base	PR	Delta
Type coverage	59.72%	59.73%	+0.00%
Strict coverage	59.30%	59.31%	+0.00%
Typed symbols	39,770	39,776	+6
Untyped symbols	27,011	27,011	0
Modules	3175	3175	0

[41tair]

There are same issues in https://github.com/langgenius/dify/blob/main/api/controllers/console/app/message.py#L539 ? Could you address it ?