feat(steward): 前端支持 off_topic 与引导话术

- assistantSessionScope.js：新增 ASSISTANT_SCOPE_ACTION_FILL_COMPOSER 常量
- assistantSuggestedActionPrefill.js：识别 fill_composer 与 payload.fill_text
- stewardPlanModel.js：normalizeStewardPlan 透传 suggestedPrompts；
  buildStewardPlanMessageText / buildStewardSuggestedActions
  新增 off_topic 分支，按钮填充输入框不提交
- useStewardPlanFlow.js：isPendingStewardActionMessage 排除 off_topic
- steward-plan-off-topic.test.mjs：覆盖 normalize/文案/按钮/兼容路径

web/src/utils/assistantSessionScope.js

@@ -2,6 +2,8 @@ import ontologyBusinessContract from '../../../shared/ontology_business_contract
 
 export const ASSISTANT_SCOPE_ACTION_SWITCH = 'switch_assistant_session'
 export const ASSISTANT_SCOPE_ACTION_UNSUPPORTED = 'unsupported_business_intent'
+// 点击后把 payload.fill_text 填充到输入框，不切换会话、不自动提交，交由用户编辑后自行发送。
+export const ASSISTANT_SCOPE_ACTION_FILL_COMPOSER = 'fill_composer'
 
 export const ASSISTANT_SCOPE_SESSION_APPLICATION = 'application'
 export const ASSISTANT_SCOPE_SESSION_EXPENSE = 'expense'
@@ -286,27 +288,84 @@ function shouldAllowContextualFollowUp(rawText, currentSessionType, options = {}
   )
 }
 
-function buildUnsupportedBusinessScopeText() {
-  const message = ONTOLOGY_BUSINESS_CONTRACT.unsupportedIntentMessage || {}
+function buildUnsupportedBusinessScopeSuggestedActions(options = {}) {
+  const sharedOptions = {
+    attachmentCount: options.attachmentCount || 0
+  }
+  const applicationAction = buildScopeSwitchAction(ASSISTANT_SCOPE_SESSION_APPLICATION, '申请下周去上海出差，支撑客户系统上线', sharedOptions)
+  const expenseAction = buildScopeSwitchAction(ASSISTANT_SCOPE_SESSION_EXPENSE, '我要报销昨天的交通费', sharedOptions)
+  const knowledgeAction = buildScopeSwitchAction(ASSISTANT_SCOPE_SESSION_KNOWLEDGE, '差旅住宿标准是多少', sharedOptions)
+  const approvalAction = buildScopeSwitchAction(ASSISTANT_SCOPE_SESSION_APPROVAL, '帮我查询待我审核的单据', sharedOptions)
+
   return [
-    message.title || '此意图系统不支持。',
-    '',
-    `当前系统支持的业务范围：${SUPPORTED_BUSINESS_SCOPE_TEXT.join('、')}。`,
-    '',
-    message.body || '你这条内容没有识别到相关财务业务意图，系统暂不支持处理。',
-    '',
-    message.retryHint || '请重新描述你的财务业务要求，例如“申请下周去上海出差”“查询我的报销单进度”或“解释差旅住宿标准”。'
-  ].join('\n')
+    { ...applicationAction, label: '去申请助手', description: '发起费用申请和事前审批' },
+    { ...expenseAction, label: '去报销助手', description: '继续处理报销和票据' },
+    { ...knowledgeAction, label: '去知识助手', description: '查看标准和流程规则' },
+    { ...approvalAction, label: '去审核助手', description: '查看待审单据和风险' }
+  ]
 }
 
-function buildUnsupportedBusinessScopeGuard() {
+function buildUnsupportedBusinessScopeText(rawText, options = {}) {
+  const message = ONTOLOGY_BUSINESS_CONTRACT.unsupportedIntentMessage || {}
+  const text = String(rawText || '').trim()
+  const intro = text
+    ? `**小财管家暂时不处理「${text}」这类内容。**`
+    : `**${message.title || '此意图系统不支持。'}**`
+  const attachmentHint = options.attachmentCount
+    ? '你刚刚上传的附件我会先保留，切换到合适场景后可以继续使用。'
+    : ''
+  return [
+    intro,
+    '',
+    '### 当前可继续的场景',
+    `- ${SUPPORTED_BUSINESS_SCOPE_TEXT[0] || '费用申请/事前审批'}`,
+    `- ${SUPPORTED_BUSINESS_SCOPE_TEXT[1] || '报销与票据识别'}`,
+    `- ${SUPPORTED_BUSINESS_SCOPE_TEXT[3] || '财务制度、报销标准和流程规则问答'}`,
+    `- ${SUPPORTED_BUSINESS_SCOPE_TEXT[4] || '预算、应收、应付等财务经营查询'}`,
+    '',
+    message.body || '这条内容没有识别到当前系统支持的财务业务意图，暂时不能继续处理。',
+    attachmentHint,
+    '你可以直接点下面的场景继续，或者重新描述你的财务业务需求。',
+    '',
+    message.retryHint || '请重新描述你的财务业务要求，例如“申请下周去上海出差”“查询我的报销单进度”或“解释差旅住宿标准”。'
+  ].filter(Boolean).join('\n')
+}
+
+export function buildUnsupportedBusinessScopeConversation(rawText, options = {}) {
+  const suggestedActions = buildUnsupportedBusinessScopeSuggestedActions(options)
+  return {
+    state_json: {
+      session_type: ASSISTANT_SCOPE_SESSION_STEWARD
+    },
+    messages: [
+      {
+        id: 'unsupported-business-intent',
+        role: 'assistant',
+        content: buildUnsupportedBusinessScopeText(rawText, options),
+        created_at: new Date().toISOString(),
+        message_json: {
+          assistant_name: '小财管家',
+          assistant_variant: 'compact_guidance',
+          orchestrator_payload: {
+            result: {
+              suggested_actions: suggestedActions
+            }
+          }
+        }
+      }
+    ]
+  }
+}
+
+function buildUnsupportedBusinessScopeGuard(rawText, options = {}) {
+  const suggestedActions = buildUnsupportedBusinessScopeSuggestedActions(options)
   return {
     targetSessionType: '',
     targetLabel: '不支持的意图',
     blocked: true,
-    text: buildUnsupportedBusinessScopeText(),
+    text: buildUnsupportedBusinessScopeText(rawText, options),
     meta: ['意图不支持'],
-    suggestedActions: [],
+    suggestedActions,
     actionType: ASSISTANT_SCOPE_ACTION_UNSUPPORTED
   }
 }
@@ -318,7 +377,7 @@ export function resolveAssistantScopeGuard(rawText, currentSessionType, options
     if (shouldAllowContextualFollowUp(rawText, normalizedCurrent, options)) {
       return null
     }
-    return normalizeText(rawText) ? buildUnsupportedBusinessScopeGuard() : null
+    return normalizeText(rawText) ? buildUnsupportedBusinessScopeGuard(rawText, options) : null
   }
 
   if (targetSessionType === normalizedCurrent) {

web/src/utils/assistantSuggestedActionPrefill.js

@@ -1,3 +1,5 @@
+import { ASSISTANT_SCOPE_ACTION_FILL_COMPOSER } from './assistantSessionScope.js'
+
 const APPLICATION_FIELD_PREFILLS = {
   time: '申请时间段：',
   time_range: '申请时间段：',
@@ -14,6 +16,7 @@ export function resolveSuggestedActionPrefill(action = {}) {
     payload.prompt_prefill
       || payload.input_prefill
       || payload.prefill_text
+      || payload.fill_text
       || ''
   ).trim()
   if (explicitPrefill) {
@@ -21,7 +24,7 @@ export function resolveSuggestedActionPrefill(action = {}) {
   }
 
   const actionType = String(action?.action_type || '').trim()
-  if (actionType !== 'prefill_composer') {
+  if (actionType !== 'prefill_composer' && actionType !== ASSISTANT_SCOPE_ACTION_FILL_COMPOSER) {
     return ''
   }