Drop generated cards; registry descriptions become Elements tooltips

- resolveRefs no longer adds cards to a diagram; it returns node id →
  description, which the page sets as the tooltip of the matching row in
  Archify's Elements panel
- hand-written cards pass through unchanged; docs and changelog

CHANGELOG.md

@@ -2,6 +2,7 @@
 
 ## 0.7.1 — 2026-10-19
 
+- **No generated cards.** The cards 0.7.0 generated under model diagrams from registry descriptions are gone; they repeated the Elements panel. The description now shows as the tooltip of the element's row in the Elements panel. Hand-written `cards:` are unchanged.
 - **Model page, Registry panel:** lists the registry files of the model, one collapsible header per file with its element count and an **Open** button that opens the registry view; expand a file to see its elements as cards. Before, all elements of all files were shown in one grid.
 
 ## 0.7.0 — 2026-10-19