fix(sync): guard against mass DELETED_IN_ROA when ROA is recovering

After a power loss + reboot, COMENZI was queryable but not yet recovered;
phase 4b-3 read it as empty and sticky-marked 3794 live orders DELETED_IN_ROA
(nulling id_comanda). check_orders_exist also swallowed Oracle errors and
returned a partial set, which callers misread as deletions.

- check_orders_exist now re-raises on Oracle error instead of returning partial
- new invoice_service.deletions_or_guard() raises MassDeletionGuard when the
  would-delete fraction is implausibly high (>30% of >=25 imported orders)
- both deletion sites (auto sync + manual refresh) skip + log on guard trip

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

api/app/routers/sync.py

@@ -846,8 +846,12 @@ async def refresh_invoices():
             existing_ids = await asyncio.to_thread(
                 invoice_service.check_orders_exist, id_comanda_list
             )
-            for o in all_imported:
-                if o["id_comanda"] not in existing_ids:
+            try:
+                to_delete = invoice_service.deletions_or_guard(all_imported, existing_ids)
+            except invoice_service.MassDeletionGuard as g:
+                logger.warning(f"Mass-deletion guard tripped during refresh: {g}")
+                to_delete = []
+            for o in to_delete:
                 await sqlite_service.mark_order_deleted_in_roa(o["order_number"])
                 orders_deleted += 1
 

api/app/services/invoice_service.py

@@ -3,6 +3,39 @@ from .. import database
 
 logger = logging.getLogger(__name__)
 
+# ── Mass-deletion safety guard ──────────────────────────────────────────────
+# If ROA appears to have lost a large fraction of its orders, it is almost
+# certainly a transient/recovery state (e.g. the DB just restarted after a power
+# loss and COMENZI hasn't finished recovering), NOT real deletions. In that case
+# we refuse to mass-mark orders as DELETED_IN_ROA — a sticky, hard-to-reverse
+# operation that nulls id_comanda. See incident 2026-06-26 (3794 false deletes).
+MASS_DELETION_ABORT_FRACTION = 0.30
+MASS_DELETION_ABORT_MIN = 25
+
+
+class MassDeletionGuard(Exception):
+    """Raised when the number of orders that would be marked deleted is
+    suspiciously high, indicating ROA is unavailable rather than truly purged."""
+
+
+def deletions_or_guard(all_imported: list, existing_ids: set) -> list:
+    """Return the subset of all_imported whose id_comanda is missing from ROA,
+    or raise MassDeletionGuard if that subset is implausibly large.
+
+    `existing_ids` MUST come from a successful check_orders_exist call — that
+    function now raises on Oracle error rather than returning a partial set, so
+    an empty result here means ROA genuinely has none of these orders.
+    """
+    missing = [o for o in all_imported if o["id_comanda"] not in existing_ids]
+    total = len(all_imported)
+    if total >= MASS_DELETION_ABORT_MIN and len(missing) > total * MASS_DELETION_ABORT_FRACTION:
+        raise MassDeletionGuard(
+            f"{len(missing)}/{total} comenzi par sterse din ROA "
+            f"(>{int(MASS_DELETION_ABORT_FRACTION * 100)}%) — posibil ROA "
+            f"indisponibil/in recuperare; marcarea DELETED_IN_ROA a fost ANULATA"
+        )
+    return missing
+
 
 def check_invoices_for_orders(id_comanda_list: list) -> dict:
     """Check which orders have been invoiced in Oracle (vanzari table).
@@ -68,7 +101,11 @@ def check_orders_exist(id_comanda_list: list) -> set:
                 for row in cur:
                     existing.add(row[0])
     except Exception as e:
+        # Do NOT swallow: a partial/empty result on error would be misread by
+        # callers as "these orders were deleted in ROA" and trigger sticky
+        # DELETED_IN_ROA marking. Propagate so the caller skips deletion.
         logger.warning(f"Order existence check failed: {e}")
+        raise
     finally:
         database.pool.release(conn)
 

api/app/services/sync_service.py

@@ -1081,8 +1081,13 @@ async def run_sync(id_pol: int = None, id_sectie: int = None, run_id: str = None
                     existing_ids = await asyncio.to_thread(
                         invoice_service.check_orders_exist, id_comanda_list
                     )
-                    for o in all_imported:
-                        if o["id_comanda"] not in existing_ids:
+                    try:
+                        to_delete = invoice_service.deletions_or_guard(all_imported, existing_ids)
+                    except invoice_service.MassDeletionGuard as g:
+                        _log_line(run_id, f"⚠ Protectie stergeri: {g}")
+                        await _record_phase_err(run_id, "mass_deletion_guard", g)
+                        to_delete = []
+                    for o in to_delete:
                         await sqlite_service.mark_order_deleted_in_roa(o["order_number"])
                         orders_deleted += 1