``build_language_schema.py`` walked ``esphome/components/`` directly,
so canonical-only directories left their deprecated aliases invisible
to the editor / dashboard autocomplete. Configs migrated only at
runtime via the ``_resolve_component_aliases`` pre-pass would still
light up as unknown top-level keys.
After building the per-component bundles, mirror each canonical
entry under every alias declared via ``ALIASES = [...]``, tagging
the duplicate with ``alias_of`` (canonical name) and
``removal_version`` (when ``ALIAS_REMOVAL_VERSION`` is set). Schema
consumers can render a deprecation hint and point users at the
canonical key without losing autocomplete on legacy configs.
Jesse Hills
71f4e36c66