fix: A1-3 publish_post deletes old file when post path changes

SPECGAPS.md

@@ -12,7 +12,7 @@ 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` does not delete old file | Fix code: add old file deletion on path change |
+| 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 |
 | A1-5 | 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 |

lib/bds/posts.ex

@@ -171,6 +171,10 @@ defmodule BDS.Posts do
             serialize_post_file(%{post | updated_at: updated_at, content: body}, published_at)
           )
 
+        if post.file_path != "" and post.file_path != relative_path do
+          delete_post_file(post)
+        end
+
         post
         |> Post.changeset(%{
           status: :published,

test/bds/posts_test.exs

@@ -188,6 +188,39 @@ defmodule BDS.PostsTest do
     refute File.exists?(full_path <> ".tmp")
   end
 
+  test "publish_post deletes old file when file path changes", %{
+    project: project,
+    temp_dir: temp_dir
+  } do
+    assert {:ok, post} =
+             BDS.Posts.create_post(%{
+               project_id: project.id,
+               title: "Moving Post",
+               content: "Body"
+             })
+
+    assert {:ok, published} = BDS.Posts.publish_post(post.id)
+    new_path = Path.join(temp_dir, published.file_path)
+    assert File.exists?(new_path)
+
+    old_relative = "posts/1999/01/moving-post.md"
+    old_full = Path.join(temp_dir, old_relative)
+    File.mkdir_p!(Path.dirname(old_full))
+    File.write!(old_full, "stale content")
+
+    import Ecto.Query
+    BDS.Repo.update_all(
+      from(p in BDS.Posts.Post, where: p.id == ^published.id),
+      set: [file_path: old_relative, content: "edited body"]
+    )
+
+    assert {:ok, republished} = BDS.Posts.publish_post(published.id)
+    assert republished.file_path == published.file_path
+
+    assert File.exists?(Path.join(temp_dir, republished.file_path))
+    refute File.exists?(old_full)
+  end
+
   test "delete_post removes the database row and published markdown file when present" do
     temp_dir =
       Path.join(System.tmp_dir!(), "bds-post-delete-#{System.unique_integer([:positive])}")