v0.6.0: drop MetaMCP from the neovim path

MetaMCP never re-dials a restarted upstream — proven for both STDIO
and STREAMABLE_HTTP upstreams — so it cannot front an ephemeral,
editor-bound MCP. The pool now fronts the nvim-mcp-bridge directly:

  Claude Code -> mcp-session-pool /p/neovim -> nvim-mcp-bridge -> nvim

The pool re-establishes on its own (_ensure_pinned re-runs initialize),
so an event-driven /repin (fired by the socket-appearance systemd.path
oneshot) actually heals the chain.

- tool names revert to two-segment mcp__neovim__vim_* (no MetaMCP
  aggregation prefix)
- agents/companion.md + skills + README: surface description and
  troubleshooting runbook rewritten for the pool->bridge->nvim chain

.claude-plugin/plugin.json

@@ -1,6 +1,6 @@
 {
 	"name": "nvim-agentic-companion",
-	"version": "0.5.0",
+	"version": "0.6.0",
 	"description": "Neovim companion that pairs the running editor (via mcp-neovim-server) with the official Claude Code IDE plugin (coder/claudecode.nvim). Provides an opinionated agent and skills for introspecting your live nvim state (buffers, keymaps, diagnostics, plugins), driving it on your behalf (open files, run keymaps, execute lua), and handing work cleanly to the in-editor Claude Code session for buffer edits.",
 	"author": {
 		"name": "oleks",