docs(agents): add YAML frontmatter to AGENTS.md documentation files

Add name and description frontmatter to the four generated AGENTS.md
documentation files so they can be discovered and indexed by NL tooling.

Co-Authored-By: Claude Code <noreply@anthropic.com>

src/agents/AGENTS.md

@@ -1,3 +1,8 @@
+---
+name: agents-directory
+description: Developer reference for all 11 Oh My OpenAgent agent definitions, factory patterns, tool restrictions, and model routing.
+---
+
 # src/agents/ — 11 Agent Definitions
 
 **Generated:** 2026-04-18

src/agents/hephaestus/AGENTS.md

@@ -1,3 +1,8 @@
+---
+name: hephaestus-agent
+description: Developer reference for the Hephaestus autonomous deep worker agent — model variants, key behaviors, and delegation patterns.
+---
+
 # src/agents/hephaestus/ -- Autonomous Deep Worker
 
 **Generated:** 2026-04-11

src/agents/prometheus/AGENTS.md

@@ -1,3 +1,8 @@
+---
+name: prometheus-agent
+description: Developer reference for the Prometheus strategic planner agent — interview flow, plan output format, and key constraints.
+---
+
 # src/agents/prometheus/ -- Strategic Planner
 
 **Generated:** 2026-04-11

src/agents/sisyphus/AGENTS.md

@@ -1,3 +1,8 @@
+---
+name: sisyphus-variants
+description: Developer reference for Sisyphus orchestrator model-specific prompt variants — selection logic and key exports.
+---
+
 # src/agents/sisyphus/ -- Orchestrator Variants
 
 **Generated:** 2026-04-11