feat(aggregations): add search activation p2 debug button to $search error banner

[DarshanaVenkatesh]

Description

Checklist

• New tests and/or benchmarks are included
• Documentation is changed or added
• If this change updates the UI, screenshots/videos are added and a design review is requested
• If this change could impact the load on the MongoDB cluster, please describe the expected and worst case impact
• I have signed the MongoDB Contributor License Agreement (https://www.mongodb.com/legal/contributor-agreement)

Motivation and Context

• Bugfix
• New feature
• Dependency update
• Misc

Open Questions

Dependents

Types of changes

• Backport Needed
• Patch (non-breaking change which fixes an issue)
• Minor (non-breaking change which adds functionality)
• Major (fix or feature that would cause existing functionality to change)

[Copilot]

Pull request overview

This PR integrates the Compass Assistant with the aggregations server error banner to provide an in-product “Debug” entry point for $search stage failures, by wiring stage context + error details into a new proactive-insights prompt.

Changes:

• Adds a new proactive-insights context (aggregation-pipeline-error) and prompt for diagnosing aggregation pipeline failures.
• Adds a “Debug” button to the aggregations server error banner for $search errors that forwards stage context to the Assistant (and closes focus mode first).
• Exposes AssistantActionsContext from the assistant package entrypoint and adds component-level tests for the new debug button behavior.

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
packages/compass-assistant/src/prompts.ts	Adds a new proactive-insights context + prompt for aggregation pipeline errors.
packages/compass-assistant/src/index.tsx	Re-exports AssistantActionsContext for consumption outside the assistant package (tests/consumers).
packages/compass-aggregations/src/components/stage-editor/stage-editor.tsx	Passes stage context and focus-mode close handler down to the error banner.
packages/compass-aggregations/src/components/server-error-banner.tsx	Renders the “Debug” button for $search errors and triggers Assistant insight flow.
packages/compass-aggregations/src/components/server-error-banner.spec.tsx	Adds coverage for debug button visibility and click behavior.