[Repo Assist] Perf: precompute entity name counts in renderEntities (O(N) vs O(N²)) (#1071)

* Perf: precompute entity name counts in renderEntities to avoid O(N²) list scanning

Previously, for each entity in the rendered list, the code scanned the
entire entities list to count duplicates (List.filter ... List.length).
With N entities this is O(N²). Replace with a single-pass List.countBy
precomputation outside the loop, reducing to O(N).

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* ci: trigger checks

---------

Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: github-actions[bot]

src/FSharp.Formatting.ApiDocs/GenerateHtml.fs

@@ -340,12 +340,14 @@ type HtmlRender(model: ApiDocModel, ?menuTemplateFolder: string) =
                         ]
                     ]
                     tbody [] [
+                        let nameCounts = entities |> List.countBy (fun e -> e.Name) |> dict
+
                         for e in entities do
                             tr [] [
                                 td [ Class "fsdocs-entity-name" ] [
                                     let nm = e.Name
 
-                                    let multi = (entities |> List.filter (fun e -> e.Name = nm) |> List.length) > 1
+                                    let multi = nameCounts.[nm] > 1
 
                                     let nmWithSiffix =
                                         if multi then

src/FSharp.Formatting.ApiDocs/GenerateMarkdown.fs

@@ -137,11 +137,13 @@ type MarkdownRender(model: ApiDocModel, ?menuTemplateFolder: string) =
                       p [ !!"Description" ]
                       p [ !!"Source" ] ] ]
                   [ AlignLeft; AlignLeft; AlignCenter ]
-                  [ for e in entities do
+                  [ let nameCounts = entities |> List.countBy (fun e -> e.Name) |> dict
+
+                    for e in entities do
                         [ [ p
                                 [ let nm = e.Name
 
-                                  let multi = (entities |> List.filter (fun e -> e.Name = nm) |> List.length) > 1
+                                  let multi = nameCounts.[nm] > 1
 
                                   let nmWithSiffix =
                                       if multi then