Filter transactions by classification status

The Transactions toolbar gains a status filter over classification
provenance — manual, AI, merchant rule, transfer match, unclassified —
alongside the existing Needs review toggle. The Source column now
renders the same human labels the filter options use instead of raw
provenance keys, so "openrouter" reads as AI and both fallback shapes
read as Unclassified.

web/src/styles.css

@@ -744,6 +744,16 @@ main {
 .search input::placeholder {
   color: #9aa6b3;
 }
+.toolbar-select {
+  height: 35px;
+  font-size: 11px;
+  padding: 0 9px;
+  border: 1px solid #dbe2ea;
+  border-radius: 5px;
+  background: #fff;
+  color: #46596a;
+  flex-shrink: 0;
+}
 .table-scroll {
   overflow-x: auto;
 }