chore: move skills and evals to plugins/bin, remove legacy root configs

Skills and evals migrated from .agents/ to plugins/bin/ plugin directory.
Remove .mcp.json, provider-manifest.sh, and skills-lock.json legacy artifacts.

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

plugins/bin/README.md

@@ -0,0 +1,40 @@
+# bin
+
+A place for things to be binned
+
+## Install
+
+**Claude Code:**
+
+```bash
+claude plugin marketplace add <owner>/<repo>
+claude plugin install bin@<marketplace-name>
+```
+
+**GitHub Copilot CLI:**
+
+```bash
+copilot plugin marketplace add <owner>/<repo>
+copilot plugin install bin
+```
+
+**Local (development):**
+
+```bash
+# Claude Code
+claude --plugin-dir ./plugins/bin
+
+# GitHub Copilot CLI
+copilot plugin install ./plugins/bin
+```
+
+## Contents
+
+| Component   | Path                                                 | Description                                                   |
+| -------------| ------------------------------------------------------| ---------------------------------------------------------------|
+| Skills      | `skills/`                                            | Slash commands available after install                        |
+| Agents      | `agents/`                                            | Role-based agents (`.md` for Claude, `.agent.md` for Copilot) |
+
+## Author
+
+Defame1297