fix(chat): use explicit trigger type check instead of heuristic for chat guard (#3419)

* fix(chat): use explicit trigger type check instead of heuristic for chat guard

* fix(chat): remove heuristic fallback from isExecutingFromChat

Use only overrideTriggerType === 'chat' instead of also checking
for 'input' in workflowInput, which can false-positive on manual
executions with workflow input.

* fix(chat): use isExecutingFromChat variable consistently in callbacks

Replace inline overrideTriggerType !== 'chat' checks with
!isExecutingFromChat to stay consistent with the rest of the function.

Author: waleedlatif1

apps/sim/app/workspace/[workspaceId]/w/[workflowId]/hooks/use-workflow-execution.ts

@@ -1124,9 +1124,7 @@ export function useWorkflowExecution() {
       {} as typeof workflowBlocks
     )
 
-    const isExecutingFromChat =
-      overrideTriggerType === 'chat' ||
-      (workflowInput && typeof workflowInput === 'object' && 'input' in workflowInput)
+    const isExecutingFromChat = overrideTriggerType === 'chat'
 
     logger.info('Executing workflow', {
       isDiffMode: currentWorkflow.isDiffMode,