sinks: read summary.imported as truth for partial-persist detection

The /import response returns activities=[input echo with errors annotated]
— its length equals input size regardless of actual persistence. The
summary{total,imported,skipped,duplicates} block is the authoritative
signal. When imported<total, raise with errorMessage + skipped + duplicates
counts.

broker_sync/sinks/wealthfolio.py

@@ -221,20 +221,35 @@ class WealthfolioSink:
         real = await self._request("POST", _IMPORT_REAL, json={"activities": valid_rows})
         real.raise_for_status()
         raw = real.json()
+        # Two observed response shapes:
+        #   - {activities:[...], importRunId:"...", summary:{total,imported,skipped,...}}
+        #   - bare list (older builds)
         if isinstance(raw, dict) and "activities" in raw:
             got = raw["activities"]
-            assert isinstance(got, list)
+            summary = raw.get("summary") if isinstance(raw.get("summary"), dict) else None
         elif isinstance(raw, list):
             got = raw
+            summary = None
         else:
             got = []
-        # Silent-drop detection: if we sent N valid rows but got 0 back, something
-        # is silently rejecting them (usually a date-format or asset-resolution
-        # quirk that check() didn't catch). Raise so the pipeline records failure
-        # instead of marking the rows as synced when they never landed.
-        if valid_rows and not got:
-            # Also surface any per-row `errors` or `warnings` from the check step
-            # — those are often the best hint about why /import dropped them.
+            summary = None
+        # Summary.imported is THE truth. The `activities` field echoes input
+        # with errors annotated — its length equals input even when zero
+        # actually persisted.
+        if summary is not None:
+            imported_n = int(summary.get("imported", 0))
+            total_n = int(summary.get("total", len(valid_rows)))
+            if imported_n < total_n:
+                err_msg = summary.get("errorMessage") or "no errorMessage"
+                skipped = int(summary.get("skipped", 0))
+                dupes = int(summary.get("duplicates", 0))
+                raise ImportValidationError(
+                    f"Wealthfolio /import persisted {imported_n}/{total_n} "
+                    f"(skipped={skipped} duplicates={dupes}). "
+                    f"errorMessage: {err_msg}"
+                )
+        # Legacy silent-drop guard for no-summary responses.
+        elif valid_rows and not got:
             first_warn = next(
                 (r.get("warnings") for r in checked if isinstance(r, dict) and r.get("warnings")),
                 None,
@@ -242,6 +257,6 @@ class WealthfolioSink:
             raise ImportValidationError(
                 f"Wealthfolio /import silently dropped all {len(valid_rows)} rows. "
                 f"First checked row: {checked[0] if checked else 'none'}. "
-                f"First warning (if any): {first_warn}"
+                f"First warning: {first_warn}"
             )
         return got