feat: issue #25 implemented - cli

lib/bds/maintenance.ex

@@ -142,4 +142,106 @@ defmodule BDS.Maintenance do
 
     {:ok, %{diff_reports: diff_reports, orphan_reports: orphan_reports}}
   end
+
+  @doc """
+  The canonical full-rebuild sequence, shared by the GUI "Rebuild Database"
+  command and the CLI `rebuild` command so the two can never drift. Each step
+  is `%{name: String.t(), work: (report -> result)}` where `report` is a
+  2-arity progress callback and a `{:error, message}` result marks failure.
+  """
+  def full_rebuild_steps(project_id) when is_binary(project_id) do
+    [
+      %{
+        name: "Rebuild Posts From Files",
+        work: fn report ->
+          {:ok, posts} =
+            rebuild_from_filesystem(project_id, "post",
+              on_progress: report,
+              rebuild_embeddings: false
+            )
+
+          report.(1.0, "Post rebuild complete")
+          %{project_id: project_id, counts: %{posts: length(posts)}}
+        end
+      },
+      %{
+        name: "Rebuild Media From Files",
+        work: fn report ->
+          {:ok, media} = rebuild_from_filesystem(project_id, "media", on_progress: report)
+          report.(1.0, "Media rebuild complete")
+          %{project_id: project_id, counts: %{media: length(media)}}
+        end
+      },
+      %{
+        name: "Rebuild Scripts From Files",
+        work: fn report ->
+          {:ok, scripts} = rebuild_from_filesystem(project_id, "script", on_progress: report)
+          report.(1.0, "Script rebuild complete")
+          %{project_id: project_id, counts: %{scripts: length(scripts)}}
+        end
+      },
+      %{
+        name: "Rebuild Templates From Files",
+        work: fn report ->
+          {:ok, templates} = rebuild_from_filesystem(project_id, "template", on_progress: report)
+          report.(1.0, "Template rebuild complete")
+          %{project_id: project_id, counts: %{templates: length(templates)}}
+        end
+      },
+      %{
+        name: "Rebuild Post Links",
+        work: fn report ->
+          :ok = BDS.Posts.rebuild_post_links(project_id, on_progress: report)
+          report.(1.0, "Post links rebuilt")
+          %{project_id: project_id}
+        end
+      },
+      %{
+        name: "Regenerate Missing Thumbnails",
+        work: fn report ->
+          result = BDS.Media.regenerate_missing_thumbnails(project_id, on_progress: report)
+          report.(1.0, "Missing thumbnails regenerated")
+          Map.put(result, :project_id, project_id)
+        end
+      },
+      %{
+        name: "Rebuild Embedding Index",
+        work: fn report -> rebuild_embedding_index(project_id, on_progress: report) end
+      }
+    ]
+  end
+
+  @doc """
+  Rebuilds the embedding index for the project, mapping backend failures to a
+  user-facing message (`{:error, message}`).
+  """
+  def rebuild_embedding_index(project_id, opts \\ []) when is_binary(project_id) do
+    on_progress = progress_callback(opts)
+
+    case Embeddings.rebuild_project(project_id, on_progress: on_progress) do
+      {:ok, rebuilt_post_ids} ->
+        on_progress.(1.0, "Embedding index rebuilt")
+
+        %{
+          project_id: project_id,
+          rebuilt_post_ids: rebuilt_post_ids,
+          rebuilt_count: length(rebuilt_post_ids)
+        }
+
+      {:error, reason} ->
+        {:error, embedding_error_message(reason)}
+    end
+  end
+
+  defp embedding_error_message(reason) do
+    detail =
+      case reason do
+        message when is_binary(message) -> message
+        {:embedding_backend_unavailable, _inner} -> "the embedding service did not start"
+        other -> inspect(other)
+      end
+
+    "Could not build the embedding index: #{detail}. The model is downloaded on first use, " <>
+      "so check your internet connection — or turn off semantic similarity in Settings."
+  end
 end