fix(model-layer): renameTable typo, dropTable IF EXISTS, model-cache flush (PR A, partial)

First (safe, contained) slice of the KYTE-#325 model-layer fixes:
- DBI::renameTable referenced an undefined $tbl_name_news (typo) → emitted a
  malformed RENAME; fixed to $tbl_name_new. Rename was effectively broken.
- DBI::dropTable now uses DROP TABLE IF EXISTS (was a bare DROP that errored on
  an already-absent table).
- DataModelController + ModelAttributeController now call Api::clearModelCache()
  after a schema change (create/rename/delete model, add/change/drop column), so
  the new struct is served immediately instead of the stale file cache (up to 1h TTL).

Remaining PR-A items (next session): enforce kyte_locked on the DDL path,
FK-dependency guard before drop column/table, and decimal (precision/scale)
support on ModelAttribute. Then PR B = the MCP schema tools.

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

Author: kennethphough

src/Core/DBI.php

@@ -716,7 +716,7 @@ public static function dropTable($tbl_name) {
 		// db connection
 		$con = self::getConnection();
 
-		$tbl_sql = "DROP TABLE `$tbl_name`";
+		$tbl_sql = "DROP TABLE IF EXISTS `$tbl_name`";
 
 		$result = $con->query($tbl_sql);
 		if($result === false) {
@@ -741,7 +741,7 @@ public static function renameTable($tbl_name_old, $tbl_name_new) {
 		// db connection
 		$con = self::getConnection();
 
-		$tbl_sql = "ALTER TABLE `$tbl_name_old` RENAME TO `$tbl_name_news`";
+		$tbl_sql = "ALTER TABLE `$tbl_name_old` RENAME TO `$tbl_name_new`";
 
 		$result = $con->query($tbl_sql);
 		if($result === false) {

src/Mvc/Controller/DataModelController.php

@@ -204,8 +204,20 @@ public function hook_response_data($method, $o, &$r = null, &$d = null) {
 
                 // return to kyte db
                 \Kyte\Core\Api::dbswitch();
+
+                // Invalidate the cached model struct for this app — the model is
+                // gone, so the next request must not load it from the stale cache.
+                \Kyte\Core\Api::clearModelCache($o->application);
+                break;
+
+            case 'new':
+            case 'update':
+                // A create or rename changed this app's model set / a struct name;
+                // flush the cached struct so the next request loads fresh rather
+                // than serving the stale cache for up to its TTL.
+                \Kyte\Core\Api::clearModelCache($o->application);
                 break;
-            
+
             default:
                 break;
         }

src/Mvc/Controller/ModelAttributeController.php

@@ -125,6 +125,10 @@ public function hook_response_data($method, $o, &$r = null, &$d = null) {
                 $tbl->save([
                     'model_definition' => json_encode($model_definition)
                 ]);
+                // Invalidate the cached model struct so the schema change (add /
+                // change / drop column) is served immediately — the file cache
+                // would otherwise serve the stale struct for up to its TTL (1h).
+                \Kyte\Core\Api::clearModelCache($tbl->application);
                 break;
 
             default: