feat: KB Accelerator — convert KB articles into interactive flows

Full-stack implementation of the KB Accelerator feature that converts
static MSP knowledge base articles into interactive troubleshooting
and procedural flows using AI.

Backend:
- Migrations 054/055: kb_imports, kb_import_nodes tables + plan_limits KB columns
- SQLAlchemy models with relationships and self-referential node hierarchy
- Text extraction service (txt, paste, docx with structural metadata)
- AI conversion service with MSP-specialist prompts for both flow types
- 8 API endpoints: upload, get, list, convert, edit node, commit, delete, quota
- Tier-gated access via plan_limits (free: 3 lifetime, pro/team: unlimited)
- 8 integration tests covering upload, get/list, quota, commit, delete

Frontend:
- TypeScript types and API client for all KB Accelerator endpoints
- Multi-step wizard page: upload → processing → review → success
- Upload screen with paste/file tabs, drag-drop, target type selector
- Two-panel review screen with source highlighting and node cards
- Per-node actions: approve, edit, regenerate, insert, delete
- Confidence color indicators (green/amber/red)
- Sidebar navigation with Sparkles icon
- Code-split lazy-loaded route at /kb-accelerator

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

frontend/src/api/index.ts

@@ -20,3 +20,4 @@ export { default as aiBuilderApi } from './aiBuilder'
 export { copilotApi } from './copilot'
 export { assistantChatApi } from './assistantChat'
 export { flowTransferApi } from './flowTransfer'
+export { kbAcceleratorApi } from './kbAccelerator'

frontend/src/api/kbAccelerator.ts

@@ -0,0 +1,76 @@
+import apiClient from './client'
+import type {
+  KBUploadResponse,
+  KBImport,
+  KBImportListResponse,
+  KBImportNode,
+  KBCommitResponse,
+  KBQuotaResponse,
+  KBListParams,
+  KBNodeEditRequest,
+  KBCommitRequest,
+} from '@/types/kbAccelerator'
+
+export const kbAcceleratorApi = {
+  async uploadText(data: { content: string; title?: string; target_type?: string }): Promise<KBUploadResponse> {
+    const formData = new FormData()
+    formData.append('content', data.content)
+    if (data.title) formData.append('title', data.title)
+    if (data.target_type) formData.append('target_type', data.target_type)
+
+    const response = await apiClient.post<KBUploadResponse>('/kb-accelerator/upload', formData, {
+      headers: { 'Content-Type': 'multipart/form-data' },
+    })
+    return response.data
+  },
+
+  async uploadFile(file: File, targetType?: string): Promise<KBUploadResponse> {
+    const formData = new FormData()
+    formData.append('file', file)
+    if (targetType) formData.append('target_type', targetType)
+
+    const response = await apiClient.post<KBUploadResponse>('/kb-accelerator/upload', formData, {
+      headers: { 'Content-Type': 'multipart/form-data' },
+    })
+    return response.data
+  },
+
+  async get(id: string): Promise<KBImport> {
+    const response = await apiClient.get<KBImport>(`/kb-accelerator/${id}`)
+    return response.data
+  },
+
+  async list(params?: KBListParams): Promise<KBImportListResponse> {
+    const response = await apiClient.get<KBImportListResponse>('/kb-accelerator', { params })
+    return response.data
+  },
+
+  async convert(id: string): Promise<{ status: string }> {
+    const response = await apiClient.post<{ status: string }>(`/kb-accelerator/${id}/convert`)
+    return response.data
+  },
+
+  async editNode(importId: string, nodeId: string, data: KBNodeEditRequest): Promise<KBImportNode> {
+    const response = await apiClient.patch<KBImportNode>(
+      `/kb-accelerator/${importId}/nodes/${nodeId}`,
+      data,
+    )
+    return response.data
+  },
+
+  async commit(id: string, data?: KBCommitRequest): Promise<KBCommitResponse> {
+    const response = await apiClient.post<KBCommitResponse>(`/kb-accelerator/${id}/commit`, data)
+    return response.data
+  },
+
+  async delete(id: string): Promise<void> {
+    await apiClient.delete(`/kb-accelerator/${id}`)
+  },
+
+  async getQuota(): Promise<KBQuotaResponse> {
+    const response = await apiClient.get<KBQuotaResponse>('/kb-accelerator/quota')
+    return response.data
+  },
+}
+
+export default kbAcceleratorApi