fix: A1-4 omit doNotTranslate from frontmatter when false per spec

SPECGAPS.md

@@ -13,7 +13,7 @@ Gap categories: **SC** = spec correct, fix code | **CS** = code correct, update
 | A1-1 | ~~No `archived→draft` or `archived→published` transition~~ | post.allium:121-122 | `unarchive_post/1` implemented, `publish_post` already handled archived→published | **Resolved:** `unarchive_post/1` in posts.ex restores content from disk, UI wired via quick actions, 4 tests added |
 | A1-2 | ~~`DeletePost` must delete translations + translation files~~ | post.allium:209-212 | `delete_post/1` now fetches translations before cascade-delete and removes their files from disk | **Resolved:** translation file cleanup added to `delete_post/1` in posts.ex, test added |
 | A1-3 | ~~Publish must delete old file when path changes~~ | engine_side_effects.allium:73-74 | `publish_post` now deletes old file when `file_path` changes | **Resolved:** old file deletion added to `publish_post/1` in posts.ex, test added |
-| A1-4 | `doNotTranslate: false` written to frontmatter despite "only when true" | frontmatter.allium:398 | `lib/bds/frontmatter.ex:38-39` writes false | Fix code: omit `doNotTranslate` when false |
+| A1-4 | ~~`doNotTranslate: false` written to frontmatter despite "only when true"~~ | frontmatter.allium:398 | `file_sync.ex:78` now converts false→nil so serializer omits the key | **Resolved:** doNotTranslate omitted from frontmatter when false, test added |
 | A1-5 | Auto-save after 3000ms idle | editor_post.allium:183-188 | No auto-save timer | Fix code: implement auto-save on idle + unmount + tab switch |
 | A1-6 | On-demand rendering in preview server | preview.allium:53-93 | Server serves static pre-generated files | Fix code: implement on-demand template rendering for post/archive/language routes |
 | A1-7 | Template lookup must use all 4 levels (post→tag→category→default) | template_context.allium:267-277 | Only levels 1 and 4 implemented; tag/category fallback unused | Fix code: implement levels 2-3 in template_selection.ex |

lib/bds/posts/file_sync.ex

@@ -75,7 +75,7 @@ defmodule BDS.Posts.FileSync do
         {"status", :published},
         {"author", post.author},
         {"language", post.language},
-        {"doNotTranslate", post.do_not_translate},
+        {"doNotTranslate", post.do_not_translate || nil},
         {"templateSlug", post.template_slug},
         {"createdAt", post.created_at},
         {"updatedAt", post.updated_at},

test/bds/posts_test.exs

@@ -188,6 +188,26 @@ defmodule BDS.PostsTest do
     refute File.exists?(full_path <> ".tmp")
   end
 
+  test "publish_post omits doNotTranslate from frontmatter when false", %{
+    project: project,
+    temp_dir: temp_dir
+  } do
+    assert {:ok, post} =
+             BDS.Posts.create_post(%{
+               project_id: project.id,
+               title: "Normal Post",
+               content: "body"
+             })
+
+    assert post.do_not_translate == false
+    assert {:ok, published} = BDS.Posts.publish_post(post.id)
+
+    full_path = Path.join(temp_dir, published.file_path)
+    file_contents = File.read!(full_path)
+
+    refute file_contents =~ "doNotTranslate"
+  end
+
   test "publish_post deletes old file when file path changes", %{
     project: project,
     temp_dir: temp_dir