fix(copilot): include a section overview in either layout when scoping search

A directory scope matched only `<section>/%`, which covers an overview stored
as `<section>/index.mdx` but not one stored as a sibling `<section>.mdx`.
Fumadocs accepts both layouts and page scope already handles both via
docsSourceCandidates, so a scoped section search could silently omit the
overview chunks — and the doc comment claimed it did not.

Every section in the tree currently uses the index.mdx layout, so nothing is
broken today; this closes the gap before someone adds a sibling overview and
gets quietly incomplete results.

Author: j15z

apps/sim/lib/copilot/docs/docs-search.test.ts

@@ -89,6 +89,15 @@ describe('searchDocs path scoping', () => {
     expect(whereText()).toContain('workflows/%')
   })
 
+  it('includes a section overview stored in either on-disk layout', async () => {
+    await searchDocs('cron', { path: 'docs/workflows' })
+    const text = whereText()
+    // `workflows/index.mdx` is inside the subtree; a sibling `workflows.mdx` is not,
+    // and fumadocs accepts either, so the scope must name it explicitly.
+    expect(text).toContain('workflows/%')
+    expect(text).toContain('workflows.mdx')
+  })
+
   it('rejects a path outside the docs corpus', async () => {
     await expect(searchDocs('cron', { path: 'files/report.pdf' })).rejects.toThrow(
       DocsSearchScopeError

apps/sim/lib/copilot/docs/docs-search.ts

@@ -56,7 +56,7 @@ export class DocsSearchScopeError extends Error {
  * `source_document` stores the en-relative mdx file path, while VFS paths mirror
  * the public URL — so a section overview is `docs/workflows.mdx` in the VFS but
  * `workflows/index.mdx` (or `workflows.mdx`) on disk. A directory scope covers
- * the whole subtree, including that overview page.
+ * the whole subtree plus the overview in either layout.
  *
  * Returns undefined for an unscoped search, which excludes `academy/` and
  * `api-reference/`: both are indexed but neither is mounted in the VFS, so a hit
@@ -89,7 +89,14 @@ function scopeCondition(path?: string) {
   }
 
   if (isDocsDir(normalized)) {
-    return like(docsEmbeddings.sourceDocument, `${escapeLikePattern(tail)}/%`)
+    // Everything under the directory, PLUS a sibling `<tail>.mdx`. Fumadocs
+    // accepts either layout for a section overview and only `<tail>/index.mdx`
+    // is inside the subtree, so matching the prefix alone would silently omit
+    // the overview for the sibling layout — page scope already covers both.
+    return or(
+      like(docsEmbeddings.sourceDocument, `${escapeLikePattern(tail)}/%`),
+      eq(docsEmbeddings.sourceDocument, `${tail}.mdx`)
+    )
   }
 
   throw new DocsSearchScopeError(