Get personalised For You feed

Rate limit: 60 requests per 60 seconds. This is a shared quota — the same budget is consumed by a group of related endpoints, so calling any of them reduces what is left for the others (you cannot call each at the full rate independently). Endpoints sharing this quota:

• GET /api/v1/feeds/following
• GET /api/v1/feeds/instrument/{marketId}
• GET /api/v1/feeds/markets/{marketId}
• GET /api/v1/feeds/news
• GET /api/v1/feeds/saved
• GET /api/v1/feeds/user/{userId}
• GET /api/v1/feeds/users/{userId}
• GET /api/v1/feeds/users/{userId}/pinned

Returns a personalised feed for the authenticated user ranked by followed users, followed instruments, prior engagement, and freshness. Ranking method is resolved via A/B experiment (Optimizely) and per-user overrides. Requires authentication — this feed is intrinsically personal.