feat: "fault tolerance" prevent agent execution error on failed retrieving

[ahmedrowaihi]

agent response should not fail, if store is not ready.
a store could change its status from time to time during adding/removing loaders.
agent should continue functioning with degrading

[Copilot]

Pull Request Overview

This PR enhances fault tolerance by ensuring agent flows degrade gracefully when document or vector stores are unavailable. Key changes include:

• Added DocumentStoreError to standardize store-related errors.
• Updated agent flow execution in buildAgentflow.ts to catch store errors and continue instead of failing.
• Wrapped store initialization and retrieval in RetrieverTool, DocStoreVector, and agentflow nodes to throw and handle DocumentStoreError.

Reviewed Changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated 4 comments.

Show a summary per file

File	Description
packages/server/src/utils/buildAgentflow.ts	Catch store errors in executeNode and executeAgentFlow, push warnings and continue execution.
packages/components/src/error.ts	Introduced DocumentStoreError class.
packages/components/nodes/vectorstores/DocumentStoreVS/DocStoreVector.ts	Throw DocumentStoreError on init failures.
packages/components/nodes/tools/RetrieverTool/RetrieverTool.ts	Catch store errors during retrieval and fallback to general knowledge.
packages/components/nodes/agentflow/Retriever/Retriever.ts	Wrap document store init/invoke to throw/handle DocumentStoreError.
packages/components/nodes/agentflow/Agent/Agent.ts	Similar error wrapping in agent knowledge store initialization.

Comments suppressed due to low confidence (1)

packages/components/nodes/tools/RetrieverTool/RetrieverTool.ts:219

• Add a unit or integration test to cover this fallback path and verify that the correct fallback string is returned when a store error occurs.

                    return 'Knowledge base temporarily unavailable. Proceeding with general knowledge.'

[ahmedrowaihi]

@HenryHengZJ resolved all copilot comments