Release v1.0.2 - Google source date-merge + description captions · eyalgal/album_slideshow

Album Slideshow v1.0.2

Photo description in captions (#17). The caption overlay can now show the photo's free-text description, read from EXIF ImageDescription, IPTC Caption-Abstract, or XMP dc:description. Add it via the card editor's Caption section (new Description option) or in YAML:
```
type: custom:album-slideshow-card
entity: camera.album_slideshow_favorites_local
caption:
  show: [date, description]
  position: bottom-left
```
Like location, description needs the metadata to be present in the file, so it is only available with the local-folder provider. Thanks to @cstack89 for the request.
Missing capture date handling for date filters (#18). Photos without an EXIF capture date used to slip past window filters like last_7_days, so old undated photos could still appear. A new Missing capture date setting controls this:
- Use upload date (default) - fall back to the photo's upload date so date windows stay meaningful.
- Include - keep undated photos in window filters (the previous behaviour).
- Exclude - drop photos that have no capture date.
It is exposed as a Missing capture date select entity and a matching control in the card editor's Slideshow settings section. Photos with neither a capture nor an upload date are kept for window filters and dropped for the strict On this day filter.

Date filters now work with Google albums whose fuller source lacks dates (#18). The integration pulls photos from two Google sources: a paginated scrape (usually has capture/upload dates) and publicalbum.org (often returns more items but no date metadata). It picked the source with more items, which could leave items with no dates at all, so use_uploaded_at had nothing to fall back on. The two sources are now merged: items from the fuller source are matched to their dated twin by photo URL and backfilled with captured_at / uploaded_at. This keeps the larger item count and restores the dates the filter needs. Thanks to @tzing for the detailed diagnosis.

Behaviour change: the default for undated photos is now Use upload date, so they are dated by their upload time instead of always passing through window filters. Set Missing capture date to Include to restore the old behaviour.
Photos that exist only in the metadata-less Google source still show no date; with Use upload date they stay lenient for window filters, exactly as before.