[Bug] Shared db.session used for side-effect writes in multimodal streaming and RAG callback handlers

[agarwalpranav0711]

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Dify version

1.15.0

Cloud or Self Hosted

Self Hosted (Docker)

Steps to reproduce

While reading PR #37895 I noticed the same db.session.commit()
side-effect bug exists in two more files that were not part of that fix.

File 1: api/core/app/apps/base_app_runner.py lines 440-442

File 2: api/core/callback_handler/index_tool_callback_handler.py
lines 49-50 and 73-89

✔️ Expected Behavior

These methods should use an independent session for side-effect writes,
same as the pattern applied in #37895.

❌ Actual Behavior

Both files still call db.session.commit() on the shared request-scoped
session. Happy to submit a PR with the fix if this looks right.

[agarwalpranav0711]

Hi! I have the fix ready locally following the same session isolation pattern (using independent session managers) established in #37895.

Could a maintainer please assign this issue to me so I can submit the PR? Thanks!