Fix file tree refresh after convert and compiler sync on set-as-main

- Convert: backend now returns parentFolderId+isNew; frontend calls
  dispatchCreateDoc directly so the new file appears without a page refresh
- Set as main: infer compiler from file extension and POST both rootDocId
  and compiler together; updateProject propagates the change to the
  editor settings dropdown and project list immediately

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

services/web/app/src/Features/Downloads/ProjectDownloadsController.mjs

@@ -264,7 +264,7 @@ async function convertDocInProject(req, res) {
     req.ip
   )
 
-  res.json({ docId: resultDocId, name: resultName })
+  res.json({ docId: resultDocId, name: resultName, parentFolderId: parentFolderId.toString(), isNew: !existingDoc })
 }
 
 export default {

services/web/frontend/js/features/file-tree/components/file-tree-item/file-tree-item-menu-items.tsx

@@ -2,6 +2,8 @@ import { useCallback } from 'react'
 import { useTranslation } from 'react-i18next'
 import * as eventTracking from '../../../../infrastructure/event-tracking'
 import { useProjectContext } from '@/shared/context/project-context'
+import { postJSON } from '@/infrastructure/fetch-json'
+import type { ProjectCompiler } from '@ol-types/project-settings'
 
 import {
   DropdownDivider,
@@ -15,7 +17,16 @@ import { findInTree } from '../../util/find-in-tree'
 import useConvertDoc from '@/features/ide-react/hooks/use-convert-doc'
 import getMeta from '@/utils/meta'
 import { isValidTeXFile } from '@/main/is-valid-tex-file'
-import { syncRootDocId } from '../../util/sync-mutation'
+
+const COMPILER_BY_EXT: Record<string, ProjectCompiler> = {
+  tex: 'pdflatex',
+  rtex: 'pdflatex',
+  ltx: 'pdflatex',
+  rnw: 'pdflatex',
+  typ: 'typst',
+  qmd: 'quarto',
+  rmd: 'quarto',
+}
 
 function FileTreeItemMenuItems() {
   const { t } = useTranslation()
@@ -74,10 +85,16 @@ function FileTreeItemMenuItems() {
     isValidTeXFile(convertEntityName)
 
   const handleSetAsMain = useCallback(async () => {
-    if (!convertEntityId) return
+    if (!convertEntityId || !convertEntityName) return
-    await syncRootDocId(projectId, convertEntityId)
+    const ext = convertEntityName.split('.').pop()?.toLowerCase() ?? ''
-    updateProject({ rootDocId: convertEntityId })
+    const newCompiler = COMPILER_BY_EXT[ext]
-  }, [convertEntityId, projectId, updateProject])
+    const body: Record<string, string> = { rootDocId: convertEntityId }
+    if (newCompiler && newCompiler !== project?.compiler) body.compiler = newCompiler
+    await postJSON(`/project/${projectId}/settings`, { body })
+    const update: Record<string, string> = { rootDocId: convertEntityId }
+    if (newCompiler) update.compiler = newCompiler
+    updateProject(update)
+  }, [convertEntityId, convertEntityName, project, projectId, updateProject])
 
   const { convert: convertToTypst } = useConvertDoc('typst', convertEntityId)
   const { convert: convertToLatex } = useConvertDoc('latex', convertEntityId)

services/web/frontend/js/features/ide-react/hooks/use-convert-doc.ts

@@ -1,5 +1,6 @@
 import { postJSON } from '@/infrastructure/fetch-json'
 import { useProjectContext } from '@/shared/context/project-context'
+import { useFileTreeData } from '@/shared/context/file-tree-data-context'
 import { useCallback, useState } from 'react'
 import {
   showExportDocumentError,
@@ -12,6 +13,7 @@ export default function useConvertDoc(
   docId: string | null
 ) {
   const { projectId } = useProjectContext()
+  const { dispatchCreateDoc } = useFileTreeData()
   const [converting, setConverting] = useState(false)
 
   const convert = useCallback(async () => {
@@ -19,17 +21,24 @@ export default function useConvertDoc(
     setConverting(true)
     hideExportDocumentError()
     try {
-      await postJSON(`/project/${projectId}/doc/${docId}/convert/${type}`, {
+      const result = await postJSON(
-        body: {},
+        `/project/${projectId}/doc/${docId}/convert/${type}`,
-      })
+        { body: {} }
+      )
       showExportDocumentSuccess(type)
+      if (result.isNew) {
+        dispatchCreateDoc(result.parentFolderId, {
+          _id: result.docId,
+          name: result.name,
+        })
+      }
     } catch (err: any) {
       const errorMessage = err?.data?.error
       showExportDocumentError(errorMessage)
     } finally {
       setConverting(false)
     }
-  }, [projectId, docId, type])
+  }, [projectId, docId, type, dispatchCreateDoc])
 
   return { convert, converting }
 }