feat(kol): add SSE streaming for prompt assist

- Extract assist runtime (prompt building, response parsing, finalize)
  from the worker into kol_assist_runtime so the sync streaming path
  and the async task path share the same logic.
- Add POST /kol/manage/assist/stream as a Server-Sent Events endpoint
  emitting start/delta/completed/error events, and wire it to a
  streamAssist helper on kolManageApi that reports ApiClientError with
  the server's error envelope.
- Stream generated content live in KolPromptEditor and KolGenerateView,
  switching KolPromptEditArea to a boolean aiBusy flag and refining the
  generator page layout.
- Add KolAssistStreamEvent to shared types.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

apps/admin-web/src/components/kol/KolPromptEditArea.vue

@@ -1,7 +1,7 @@
 <script setup lang="ts">
 import { computed, h, ref } from "vue";
 import { useI18n } from "vue-i18n";
-import { ExperimentOutlined, ThunderboltOutlined, LoadingOutlined } from "@ant-design/icons-vue";
+import { ExperimentOutlined, ThunderboltOutlined } from "@ant-design/icons-vue";
 import type { KolVariableDefinition, KolVariableType } from "@geo/shared-types";
 import { Modal } from "ant-design-vue";
 
@@ -13,7 +13,7 @@ import {
 const props = defineProps<{
   content: string;
   variables: KolVariableDefinition[];
-  aiTaskId: string | null;
+  aiBusy: boolean;
 }>();
 
 const emit = defineEmits<{
@@ -37,6 +37,12 @@ type PointerSelectionState = {
   startY: number;
 };
 
+type OverlaySelectionRange = {
+  start: number;
+  end: number;
+  direction: "forward" | "backward";
+};
+
 let pointerSelectionState: PointerSelectionState | null = null;
 
 const editorPlaceholder = "在这里输入提示词内容，可以使用 {{变量名}} 引用左侧定义的变量";
@@ -160,7 +166,18 @@ function handleHighlightPointerUp(event: PointerEvent) {
     return;
   }
 
-  if (hasOverlaySelection(highlight)) {
+  const overlaySelection = getOverlaySelectionRange(highlight);
+  if (overlaySelection) {
+    const scrollTop = textarea.scrollTop;
+    const scrollLeft = textarea.scrollLeft;
+
+    textarea.setSelectionRange(
+      overlaySelection.start,
+      overlaySelection.end,
+      overlaySelection.direction,
+    );
+    focusTextareaWithoutScroll(textarea);
+    restoreTextareaScroll(textarea, scrollTop, scrollLeft);
     return;
   }
 
@@ -210,6 +227,29 @@ function hasOverlaySelection(container: HTMLElement): boolean {
   return !!anchorNode && !!focusNode && container.contains(anchorNode) && container.contains(focusNode);
 }
 
+function getOverlaySelectionRange(container: HTMLElement): OverlaySelectionRange | null {
+  if (!hasOverlaySelection(container)) {
+    return null;
+  }
+
+  const selection = window.getSelection();
+  if (!selection) {
+    return null;
+  }
+
+  const anchorIndex = resolveCaretIndex(container, selection.anchorNode, selection.anchorOffset);
+  const focusIndex = resolveCaretIndex(container, selection.focusNode, selection.focusOffset);
+  if (anchorIndex === null || focusIndex === null) {
+    return null;
+  }
+
+  return {
+    start: Math.min(anchorIndex, focusIndex),
+    end: Math.max(anchorIndex, focusIndex),
+    direction: anchorIndex <= focusIndex ? "forward" : "backward",
+  };
+}
+
 function getCaretIndexFromPoint(container: HTMLElement, event: PointerEvent): number {
   const browserIndex = getBrowserCaretIndex(container, event);
   if (browserIndex !== null) {
@@ -433,7 +473,7 @@ function escapeAttribute(value: string): string {
         v-model:value="aiDescription"
         class="ai-input"
         :placeholder="t('kol.manage.editor.aiPlaceholder')"
-        :disabled="!!aiTaskId"
+        :disabled="aiBusy"
         @press-enter="handleAiGenerate"
       >
         <template #prefix>
@@ -443,7 +483,7 @@ function escapeAttribute(value: string): string {
       <a-button
         type="primary"
         class="ai-btn"
-        :loading="!!aiTaskId"
+        :loading="aiBusy"
         @click="handleAiGenerate"
       >
         <template #icon><ThunderboltOutlined /></template>
@@ -451,20 +491,15 @@ function escapeAttribute(value: string): string {
       </a-button>
       <a-button
         class="ai-btn"
-        :disabled="!content || !!aiTaskId"
+        :disabled="!content || aiBusy"
         @click="emit('ai-optimize')"
       >
         {{ t('kol.manage.editor.aiOptimize') }}
       </a-button>
+      <span v-if="aiBusy" class="ai-status-text">AI 正在处理中...</span>
     </div>
 
     <div class="editor-container">
-      <div v-if="aiTaskId" class="ai-loading-overlay">
-        <div class="loading-content">
-          <LoadingOutlined class="loading-icon" />
-          <span>AI 正在思考中...</span>
-        </div>
-      </div>
       <div
         ref="highlightRef"
         class="prompt-highlight"
@@ -512,6 +547,14 @@ function escapeAttribute(value: string): string {
   flex-shrink: 0;
 }
 
+.ai-status-text {
+  display: inline-flex;
+  align-items: center;
+  color: #722ed1;
+  font-size: 13px;
+  white-space: nowrap;
+}
+
 .editor-container {
   flex: 1;
   position: relative;
@@ -576,28 +619,4 @@ function escapeAttribute(value: string): string {
   color: #bfbfbf;
 }
 
-.ai-loading-overlay {
-  position: absolute;
-  top: 0;
-  left: 0;
-  right: 0;
-  bottom: 0;
-  background: rgba(255, 255, 255, 0.7);
-  z-index: 10;
-  display: flex;
-  align-items: center;
-  justify-content: center;
-}
-
-.loading-content {
-  display: flex;
-  flex-direction: column;
-  align-items: center;
-  gap: 12px;
-  color: #722ed1;
-}
-
-.loading-icon {
-  font-size: 32px;
-}
 </style>