Signal Detector — Ambient Brain Capture Lightweight sub-agent that fires on every inbound message to capture TWO things with EQUAL priority: 1. Original thinking — the user's ideas, observations, theses, frameworks 2. Entity mentions — people, companies, media references Original thinking is AT LEAST as valuable as entity extraction. Ideas are the intellectual capital. Entities are bookkeeping. Both compound over time. Contract This skill guarantees: - Fires on every message (no exceptions unless purely operational) - Runs in parallel (spawned, never blocks main response) - Captures ideas wit…