More cover exclusions

mix.exs

@@ -21,20 +21,36 @@ defmodule MusicLibrary.MixProject do
     ]
   end
 
-  # Modules excluded from coverage accounting: cron-only workers that run
-  # operations incompatible with the Ecto sandbox (VACUUM / OPTIMIZE outside a
-  # transaction) or whose behaviour beyond a delegate call is untestable, and
-  # all Mix tasks (developer tooling not exercised by the application test
+  # Modules excluded from coverage accounting:
+  #
+  # - Cron-only workers that run operations incompatible with the Ecto sandbox
+  #   (VACUUM / OPTIMIZE outside a transaction) or whose behaviour beyond a
+  #   delegate call is untestable.
+  # - Ecto.Repo shells (boilerplate plus platform-exclusive `extension_path/1`
+  #   branches that cannot all execute on a single host).
+  # - Phoenix generator output (ErrorHTML, the MusicLibraryWeb `use` entrypoint)
+  #   with no application behaviour.
+  # - Telemetry instrumentation whose write paths are only reachable from real
+  #   `:telemetry.execute/3` events emitted by external libraries.
+  # - Vendored `SqliteVec.*` library code under `lib/sqlite_vec/`.
+  # - All Mix tasks (developer tooling not exercised by the application test
   #   suite).
   defp ignored_coverage_modules do
     [
       MusicLibrary.Release,
+      MusicLibrary.Repo,
+      MusicLibrary.BackgroundRepo,
       MusicLibrary.Worker.RepoVacuum,
       MusicLibrary.Worker.RepoOptimize,
       MusicLibrary.Worker.SendRecordsOnThisDayEmail,
       MusicLibrary.Worker.RefreshScrobbles,
       MusicLibrary.Worker.BackfillScrobbledTracks,
-      ~r/^Mix\.Tasks\./
+      MusicLibraryWeb,
+      MusicLibraryWeb.ErrorHTML,
+      MusicLibraryWeb.Telemetry,
+      MusicLibraryWeb.Telemetry.Storage,
+      ~r/^Mix\.Tasks\./,
+      ~r/^SqliteVec\./
     ]
   end