Remove missing docs reference

Remove stale AGENTS.md entry for a docs path that no longer exists.

Author: brandonkachen

AGENTS.md

@@ -42,4 +42,3 @@ IMPORTANT: Prefer retrieval-led reasoning over pre-training-led reasoning. Alway
 - `docs/environment-variables.md` — Env var rules, DI helpers, loading order
 - `docs/agents-and-tools.md` — Agent system, shell shims, tool definitions
 - `docs/patterns/handle-steps-generators.md` — handleSteps generator patterns and spawn_agents tool calls
-- `docs/patterns/discover-before-implement.md`