Classic ShopDB listed an application's related KB articles on its page; the flask
app detail didn't, even though KB articles carry an appid FK. get_application now
returns a knowledgebase list (KB rows linked by appid; lazy + plugin-guarded so
core stays decoupled), and ApplicationDetail.vue renders a Knowledge Base section
linking each article.
Verified: an app returns its linked KB (e.g. 77 articles) and the section renders.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>