v1.7.3

Fixed — bws-media-picker fallback corrupting tag string on reopen

• assets/js/image-tag-controls.js: media picker stored the selected attachment's source_url in the option key. URLs contain : (scheme) and / characters that collide with GB's tag-string parser — parse_options() splits on : with no escape sequence, so fallback:https://host/path.jpg round-tripped as fallback:https only, dropping the actual URL on modal reopen. Picker now stores the attachment ID (att.id) and re-fetches the preview URL via wp.data core store getMedia(id) for display. bws_handle_media_fallback() already accepted IDs (legacy code path), so render-side behavior is unchanged for existing URL-based tags; only the tag-string round-trip is fixed.

Docs

• docs/gb-constraints.md: new §Tag-string-unsafe values documenting the colon/pipe parser limitation, workarounds (store ID, protocol-relative, encode), and pointer to the bws-media-picker ID-storage decision.