Human-readable release URLs; manifest-based auto-discovery

Added

• Release URLs now include a human-readable slug — links look like /release/rel_...-whats-new-in-v2 instead of bare IDs; old bare-ID links redirect permanently. The slugged canonical URL is now carried through MCP tool outputs, Atom feeds, webhook payloads, Slack cards, and digest emails.
• releases.json v2 manifest — declare where your release notes live at /.well-known/releases.json; the registry auto-creates sources from feed, github, and appstore locators and reconciles product metadata, tags, and identity fields without overwriting curator edits.
• Docs pages now support deep links and show an "On this page" rail — all /docs/ section headings have stable anchor IDs, authored cross-section links resolve correctly, and a scrolling sidebar highlights the active section.
• Mobile app discovery from platform link files — iOS apps are auto-discovered from /.well-known/apple-app-site-association and queued as paused candidates for curator review; no bespoke manifest required.

Changed

• Org overviews now adapt to release velocity — active orgs refresh on a 2-day cycle with a 30-day activity window; quiet orgs use a 90-day fallback; per-org cadence overrides are supported.
• Collection, category, and release-list pages load faster — markdown is now rendered server-side; shiki and react-markdown no longer ship to the browser on list views.

Fixed

• Product rows in org overview panels now link to their product pages.
• Hidden sources no longer appear on public org, product, or search pages — a filtering gap in release feeds, source rows, and organization search results has been corrected.