v1.1.0

v1.1.0: rename to Support Center, add video articles

Rename: plugin name/description, post type labels and the category
taxonomy now read "Support Center" / "Support Article". The CPT slug
stays help_article and the shortcode stays [help-center] — renaming
either would orphan existing articles and break the embedding page.

Video articles: a new Video meta box takes a Vimeo link and renders the
player above the article body, so an article can be a video instead of
text by leaving the body empty. Body text still renders underneath when
present. Clearing the field deletes the meta rather than storing an
empty value, so the article reverts to text only. The list marks video
articles with a play badge and falls back to a label when there is no
body text to build an excerpt from.

Also fixes the pre-existing bare-URL embed conversion, now shared with
the meta field through one parser:

• it dropped the unlisted-video hash, so vimeo.com// embedded
  as a private video that would not play. Now emitted as ?h=,
  along with player.vimeo.com, /channels/ and /groups/ URL shapes.
• its pattern could match a Vimeo URL already inside a tag attribute.
  the_content runs WP autoembed first, so a standalone link is often
  already an iframe, and rewriting its src corrupted the markup. A
  lookbehind now keeps the conversion off attribute values.

Co-Authored-By: Claude Opus 5 (1M context) noreply@anthropic.com