fix: delete AppConnect's token variable when linking its account fails, so Save can be retried

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

backend/.sqlx/query-92d2202c8752ab24777daa5c46b14ae645076a85940cef890083a45301a7cd62.json

@@ -1,6 +1,6 @@
 {
   "db_name": "PostgreSQL",
-  "query": "SELECT EXISTS(SELECT 1 FROM variable WHERE account = $1 AND workspace_id = $2)",
+  "query": "SELECT EXISTS(SELECT 1 FROM variable WHERE account = $1 AND workspace_id = $2 AND path <> $3)",
   "describe": {
     "columns": [
       {
@@ -12,6 +12,7 @@
     "parameters": {
       "Left": [
         "Int4",
+        "Text",
         "Text"
       ]
     },
@@ -19,5 +20,5 @@
       null
     ]
   },
-  "hash": "7aa589db3199d7f727cc69e63e1281b7ed329ff0c9d1617747f4ccd6014720cf"
+  "hash": "92d2202c8752ab24777daa5c46b14ae645076a85940cef890083a45301a7cd62"
 }

frontend/src/lib/components/AppConnectInner.svelte

@@ -1005,10 +1005,19 @@
 						}
 					})
 					if (accountData) {
-						await OauthService.createAccount({
-							workspace: effectiveWorkspace,
-							requestBody: { ...accountData, variable_path: tokenPath }
-						})
+						try {
+							await OauthService.createAccount({
+								workspace: effectiveWorkspace,
+								requestBody: { ...accountData, variable_path: tokenPath }
+							})
+						} catch (e) {
+							// An unlinked token never refreshes, and its path would block a retry.
+							await VariableService.deleteVariable({
+								workspace: effectiveWorkspace,
+								path: tokenPath
+							}).catch(() => {})
+							throw e
+						}
 					}
 					resourceValue['token'] = `$var:${tokenPath}`
 				}