---
phase: 02-external-sync-integrations
plan: 04
subsystem: database
tags: [merge, conflicts, overrides, recipients-api]
requires:
  - phase: 02-external-sync-integrations
    provides: ingest/link/projection + scheduler status
provides:
  - Precedence-aware recipient merge path
  - Conflict note capture and persistence hooks
  - Manual override persistence behavior
  - Recipient API discrepancy warning metadata
affects: [dashboard, detail-editing]
tech-stack:
  added: []
  patterns: [recipient-scoped-merge, warning-metadata]
key-files:
  created:
    - crates/service/src/sync/merge.rs
    - crates/service/src/sync/conflict_notes.rs
    - crates/service/tests/merge_pipeline_tests.rs
  modified:
    - crates/service/src/db/repository.rs
    - crates/service/src/api/recipients.rs
    - crates/core/src/domain/recipient.rs
requirements-completed: [DATA-01, DATA-02, DATA-03, DATA-07]
duration: 45min
completed: 2026-02-27
---

# Phase 2 Plan 04 Summary

**A unified merge pipeline now combines provider data safely, preserves manual overrides, and exposes discrepancy metadata for UI warnings.**

## Accomplishments
- Implemented recipient merge engine with source precedence and partial-failure-friendly unresolved field handling.
- Added conflict note model + repository persistence hooks and override application support.
- Extended recipient API snapshot payload to include discrepancy warning and tooltip metadata.

## Verification
- `cargo test -p service merge_precedence -- --nocapture`
- `cargo test -p service merge_conflicts_and_overrides -- --nocapture`
- `cargo test -p service merge_pipeline_tests -- --nocapture`

## Deviations
- None.