bug: merge suggestion action unreliable on contacts and organizations pages

[RAWx18]

Short Summary

The Merge Suggestion button on Contacts and Organizations pages may not function correctly or lacks proper validation, error handling, and pipeline guarantees.

Steps to Reproduce

1. Navigate to the Contacts page.
2. Observe any Merge Suggestion button for duplicate or similar contacts.
3. Trigger the Merge Suggestion action.
4. Repeat the same steps on the Organizations page.
5. Monitor UI feedback, backend responses, and resulting data state.

Expected Behavior

Merge Suggestion should deterministically evaluate merge candidates, perform pre-merge validation, surface clear success or failure states, and safely execute merges through a defined pipeline.

Actual Behavior

It is unclear whether the Merge Suggestion action executes correctly.
If it runs, it lacks proper checks, validation, and error handling.
If it does not run, the action silently fails with no visible feedback or pipeline execution.

Environment

• OS: Linux
• Browser: Chrome
• Environment: Local development
• Routes: /signals/contacts, /signals/organizations

Additional Context

Action items:

• Audit whether Merge Suggestion is wired end-to-end (UI → API → merge logic).
• If functional:
  • Add deterministic pre-merge checks (identity confidence, conflicting fields).
  • Add explicit error handling and user-visible failure states.
  • Log merge decisions and outcomes.
• If non-functional:
  • Implement a proper merge suggestion pipeline:
    • Candidate generation (similarity scoring across identifiers).
    • Confidence thresholding.
    • Dry-run preview.
    • Explicit approval step.
    • Idempotent merge execution.
      This is a data integrity risk; silent or incorrect merges will corrupt contacts and org graphs.
      Fix must prioritize safety, traceability, and determinism.