feat: initial commit - oncology literature search platform

OncoLit: a multi-tenant oncology literature search, feed, and
collaboration platform. Built with FastAPI + Vue 3 + PostgreSQL.
Includes PubMed pipeline, drug approvals, AI summaries, and
systematic review tools.

frontend/public/manifest.json

@@ -0,0 +1,17 @@
+{
+  "name": "SciLit Oncology - 肿瘤科文献中心",
+  "short_name": "SciLit Oncology",
+  "description": "全球肿瘤学进展，每日自动推送。覆盖 NEJM/Lancet/JAMA/JCO 等顶级期刊。",
+  "start_url": "/app/feed",
+  "display": "standalone",
+  "background_color": "#f5f7fa",
+  "theme_color": "#1a5276",
+  "orientation": "any",
+  "icons": [
+    { "src": "/icon-192.png", "sizes": "192x192", "type": "image/png" },
+    { "src": "/icon-512.png", "sizes": "512x512", "type": "image/png" }
+  ],
+  "categories": ["medical", "education", "productivity"],
+  "lang": "zh-CN",
+  "scope": "/"
+}