feat: harden loose-offline sync for user JWT, schema, and console ops

Enable Binding-scoped agent push/pull, empty-table schema ensure, SyncPage inspect/drop-table, default module import, and agent-bound publish docs from the 宇恒联调意见.

Co-authored-by: Cursor <cursoragent@cursor.com>

platform/internal/dbsync/push_test.go

@@ -37,10 +37,11 @@ func TestTableInChannel(t *testing.T) {
 		Local:  Endpoint{Tables: []string{"orders"}},
 		Remote: Endpoint{Tables: []string{"orders"}},
 	}
-	if !tableInChannel(ch, "orders") {
-		t.Fatal("expected in")
+	// Z4：通道表白名单不再拒收
+	if !tableInChannel(ch, "orders") || !tableInChannel(ch, "other") {
+		t.Fatal("expected any non-empty table accepted")
 	}
-	if tableInChannel(ch, "other") {
-		t.Fatal("expected out")
+	if tableInChannel(ch, "") {
+		t.Fatal("empty table rejected")
 	}
 }