catalog: add open_path for apps whose UI isn't at / (gokapi=/admin, ghost=/ghost/)

New .felhom.yml field consumed by the controller's Megnyitás link. Audit of all 53 templates: only
gokapi (file-share index redirects away) and ghost (bare / is the public blog; admin at /ghost/) need it;
the rest serve/redirect usefully at root. onlyoffice is API-only (status page at /) — left at root.

templates/ghost/.felhom.yml

@@ -8,6 +8,8 @@ description: "Professzionális blog és hírlevél platform"
 category: "productivity"
 subdomain: "blog"
 slug: "ghost"
+# Bare "/" is the public blog; the admin panel / setup wizard lives at /ghost/.
+open_path: "/ghost/"
 
 # --- Resource hints (displayed on deploy screen) ---
 resources:

templates/gokapi/.felhom.yml

@@ -8,6 +8,8 @@ description: "Ideiglenes fájlmegosztás lejáró linkekkel"
 category: "files"
 subdomain: "share"
 slug: "gokapi"
+# Gokapi's bare "/" redirects away (file-share index); the admin/login UI is at /admin.
+open_path: "/admin"
 
 # --- Resource hints (displayed on deploy screen) ---
 resources: