refactor(docs): move catalog index into star-systems directory

Renamed catalog-index.md to star-systems/catalog.md where it
belongs. Updated references in wiki root and star-systems index.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

wiki/index.md

@@ -35,7 +35,7 @@
 - **[Concepts](concepts/index.md)** — Fact catalog, entity attributes, relationship states.
 - **[Triangles](triangles/index.md)** — Relationship structures ([Hub Power](triangles/hub-power.md)).
 - **[Authoring Guides](authoring/)** — Monologue guide, cultural generation, content templates.
-- **[Catalog Index](catalog-index.md)** — All 301 systems by GJ designation.
+- **[Full Catalog](star-systems/catalog.md)** — All 301 systems by GJ designation.
 
 ---
 

wiki/star-systems/index.md

@@ -41,4 +41,4 @@
 
 ## Full Catalog
 
-See [catalog-index.md](../catalog-index.md) for all 301 systems by GJ designation.
+See [catalog.md](catalog.md) for all 301 systems by GJ designation.