Hub: Multi-product dashboard (Uteke, Cora, TrapFall, Rungu)

## Description
Dashboard showing all CodeCora ecosystem products with status and quick actions.

## Products
- 🧠 Uteke — Memories, Graph
- 🔍 Cora — Recent reviews, SARIF files
- 🪤 TrapFall — Error groups, crashes
- 👂 Rungu — Code intel, queries

## Features
- Product cards with status indicators
- Quick stats per product
- Recent activity feed across all products
