feat(library): exclude configured folders from scanning and analysis

services/api/migrations/00017_scan_excluded_dirs.sql

@@ -0,0 +1,29 @@
+-- +goose Up
+ALTER TABLE library_sources ADD COLUMN excluded_dirs text[] NOT NULL DEFAULT '{}';
+
+-- +goose StatementBegin
+CREATE FUNCTION library_path_excluded(rel_path text, excluded_dirs text[])
+RETURNS boolean LANGUAGE sql IMMUTABLE PARALLEL SAFE AS $$
+  SELECT EXISTS (
+    SELECT 1 FROM unnest(excluded_dirs) AS d(dir)
+    WHERE rel_path = dir OR starts_with(rel_path, dir || '/')
+  );
+$$;
+-- +goose StatementEnd
+
+-- Keep historical jobs and files; only tracks whose every known file is excluded are suppressed.
+-- +goose StatementBegin
+CREATE FUNCTION library_track_scan_excluded(track uuid)
+RETURNS boolean LANGUAGE sql STABLE AS $$
+  SELECT EXISTS (SELECT 1 FROM media_files WHERE track_id = track)
+    AND NOT EXISTS (
+      SELECT 1 FROM media_files f JOIN library_sources s ON s.id = f.source_id
+      WHERE f.track_id = track AND NOT library_path_excluded(f.rel_path, s.excluded_dirs)
+    );
+$$;
+-- +goose StatementEnd
+
+-- +goose Down
+DROP FUNCTION library_track_scan_excluded(uuid);
+DROP FUNCTION library_path_excluded(text, text[]);
+ALTER TABLE library_sources DROP COLUMN excluded_dirs;