docs: update AGENTS.md structure to reflect plugins/ and marketplace

Adds plugins/, .agents/evals/, and .claude-plugin/ to the structure
section. Clarifies that .agents/skills/ contains directly-deployed skills
only; marketplace and factory skills now live in plugins/kyberforge/.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

AGENTS.md

@@ -5,7 +5,10 @@ This repo is the global AI development configuration repository — the authorit
 ## Structure
 
 - `core/` — provider-agnostic source of truth (plain language, no tool-specific references)
-- `.agents/skills/` — canonical skills location (Agent Skills standard); deployed to `~/.agents/skills/` via `install.sh`
+- `.agents/skills/` — directly-deployed skills (Agent Skills standard); deployed to `~/.agents/skills/` via `install.sh`; marketplace and factory skills live in `plugins/kyberforge/` instead
+- `.agents/evals/` — eval.yaml files for skills not bundled into a plugin
+- `.claude-plugin/` — marketplace manifest (`marketplace.json`); read by both Claude Code and Copilot CLI
+- `plugins/` — installable plugin units; each is self-contained (skills, agents, hooks, MCP servers, bundled assets); install separately via `claude plugin install <name>@holocron`
 - `providers/claude-code/` — Claude Code adapter (deployed to `~/.claude/` via `install.sh`)
 - `docs/` — project documentation, PRDs, and issues
 - `scripts/` — install.sh (sync.sh and init-project.sh come in Chunk 6)