Add vendor workspace import and pricing export workflow

bible-local/03-database.md

@@ -107,11 +107,33 @@ Database: `RFQ_LOG`
 | `stock_log` | Latest stock qty by partnumber (pricelist enrichment) | SELECT |
 | `qt_projects` | Projects | SELECT, INSERT, UPDATE |
 | `qt_client_local_migrations` | Migration catalog | SELECT only |
-| `qt_client_schema_state` | Applied migrations state | SELECT, INSERT, UPDATE |
+| `qt_client_schema_state` | Applied migrations state + client operational status per `username + hostname` | SELECT, INSERT, UPDATE |
 | `qt_pricelist_sync_status` | Pricelist sync status | SELECT, INSERT, UPDATE |
 | `qt_partnumber_books` | Partnumber book snapshots (written by PriceForge) | SELECT |
 | `qt_partnumber_book_items` | PN→LOT mapping rows (written by PriceForge) | SELECT |
-| `qt_vendor_partnumber_seen` | Vendor PN tracking for unresolved/ignored BOM rows (`is_ignored`) | INSERT, UPDATE |
+| `qt_vendor_partnumber_seen` | Vendor PN tracking for unresolved/ignored BOM rows (`is_ignored`) | INSERT only for new `partnumber`; existing rows must not be modified |
+
+`qt_client_schema_state` current contract:
+
+- identity key: `username + hostname`
+- migration state:
+  `last_applied_migration_id`, `app_version`, `last_checked_at`, `updated_at`
+- operational state:
+  `last_sync_at`, `last_sync_status`
+- queue health:
+  `pending_changes_count`, `pending_errors_count`
+- local dataset size:
+  `configurations_count`, `projects_count`
+- price context:
+  `estimate_pricelist_version`, `warehouse_pricelist_version`, `competitor_pricelist_version`
+- last known sync problem:
+  `last_sync_error_code`, `last_sync_error_text`
+
+`last_sync_error_*` source priority:
+
+1. blocked readiness state from `local_sync_guard_state`
+2. latest non-empty `pending_changes.last_error`
+3. `NULL` when no known sync problem exists
 
 ### Grant Permissions to Existing User