v0.2.0: broaden tools, ship neovim MCP server, namespace agent

- agents/companion.md: expand tools to full editor + filesystem + web set
  and grant mcp__neovim__* so the agent can drive nvim directly
- skills/*: each skill's allowed-tools also gains mcp__neovim__*
- .mcp.json: ship the mcp-neovim-server config with the plugin so
  installing the plugin auto-wires the editor MCP (uses default socket
  /run/user/1000/nvim.sock — adjust if your uid differs)

.mcp.json

@@ -0,0 +1,11 @@
+{
+  "mcpServers": {
+    "neovim": {
+      "command": "npx",
+      "args": ["-y", "mcp-neovim-server"],
+      "env": {
+        "NVIM_SOCKET_PATH": "/run/user/1000/nvim.sock"
+      }
+    }
+  }
+}