Record Phase 4 iteration 1 in PROGRESS.md

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

codebase-review/PROGRESS.md

@@ -145,4 +145,29 @@ fallback already guarded `len >= 2`).
 
 ## Phase 3 — Frontend Data Layer & Feedback ⏳ NOT STARTED
 
-## Phase 4 — UX, Trust & Features ⏳ NOT STARTED
+## Phase 4 — UX, Trust & Features 🔄 ITERATION 1 DONE
+
+Iteration 1 completed 2026-06-10. The plan marks 4.x items independent; this
+iteration delivered the highest-impact slice.
+
+| Plan item | Status | Commit |
+|---|---|---|
+| 4.1 Sync Status page + nav badge (UX-17, the #1 trust feature) | ✅ | `4ceb675` |
+| 4.3 Localization: shared es-CR dates module, stray labels | ✅ | (l10n) |
+| 4.5 Undo grace (5s + Deshacer) for transaction deletes | ✅ | `629d118` |
+| 4.8 CSV export endpoint + Budget/Salarios buttons | ✅ | `571428f` |
+| 4.7 picks: aria-pressed, deferred row styling, override hint | ✅ | `b3a7f51` |
+
+**Sync Status design:** per-source health derived entirely from existing data
+(`max(created_at)` per source + cadence thresholds: BAC 7d, salary 35d,
+municipal/pensions 40d, exchange rate 1d) — no n8n integration required for v1.
+Endpoint tested; verified live (it immediately flagged the dev DB's stale data).
+
+**Deferred to iteration 2** (each independent): 4.2 import review & dedup
+transparency (L — includes the reference-hash tightening, which must migrate
+existing hashes to avoid breaking dedup), 4.4 transaction search-everywhere is
+**not needed** (search already applies to all sources — UX-04 was a false
+positive) but bulk operations remain (L), 4.6 mobile card layout (M), 4.7
+remainder: shared period navigator, editable pension assumptions, cycle filter
+on all Analytics charts, empty-state actions, dirty-form guard, breadcrumb,
+meter labels. 4.9 wishlist unscheduled.