Smart Element slot overrides, bindable-variable discovery, and single-image Braze upload

What shipped

• •orbit_compose_stripo_email now accepts a slot_values map on any module in the sequence. Pass slot key → content pairs and Orbit injects them into the module's Smart Element placeholders at compose time. Lets you run the same modular email template with different headlines, offer copy, or imagery per audience without touching Stripo's editor between sends. Slot keys come from the slot_definitions field on each module (see below).
• •orbit_list_stripo_modules now returns slot_definitions alongside each module — a map of bindable variable names to their kind (text, url, image_src, image_alt). Use these keys when building slot_values for orbit_compose_stripo_email. Modules without Smart Element bindings return null, so you can see at a glance which modules support per-send variation.
• •New tool orbit_upload_image_to_braze — upload a single image to the Braze media library and get back a hosted CDN URL. Accepts a remote URL (Braze fetches it server-side), a local file path (base64-encoded, 4 MB cap), or raw base64 data. The returned URL is ready to drop directly into slot_values or any Braze template without opening the Braze console.