fix: crash 'list' object has no attribute 'keys' on image upload, output disappearing on error

Root cause: layout_schema.regions is a list of region dicts, not a dict.
_log_ocr_layers() was calling .keys() on it, causing agent_error.

Also fixed: ProcessSection now stays visible after streaming ends (error or
completion), so generated content is not lost. Header shows ✓/✕/pulse indicators.
Error handler now refreshes session state for partial JRXML download.

frontend/src/App.vue

@@ -103,6 +103,7 @@ async function handleSend(text: string, files: File[]) {
       onAgentError(data) {
         chat.setError(data.error)
         chat.addMessage({ role: 'assistant', content: `执行异常: ${data.error}`, type: 'error' })
+        setTimeout(() => session.refreshFromState({}), 500)
       },
     })
   } catch (e: any) {