Initial commit: nvim-agentic-companion plugin

Adds a Claude Code agent and three skills for collaborating with the
user's running Neovim instance via mcp-neovim-server and the official
coder/claudecode.nvim plugin:

- agents/companion.md — the nvim companion identity, prefers runtime
  introspection over training-data guessing
- skills/editor-introspect — read-only queries against the live editor
- skills/editor-act — safe driving (open, jump, toggle, run); no buffer edits
- skills/claude-code-handoff — delegate buffer edits to the in-editor
  Claude Code session so users get a diff to accept or reject

README.md

@@ -0,0 +1,54 @@
+# nvim-agentic-companion
+
+A Claude Code plugin that turns the user's running Neovim into a first-class collaborator.
+
+It assumes two things are already wired up:
+
+1. **`mcp-neovim-server`** registered as an MCP server in Claude Code, pointed at the nvim RPC socket (default `/run/user/1000/nvim.sock`). NixVim's `extraConfigLuaPre` starts the server on that socket at editor startup.
+2. **`coder/claudecode.nvim`** loaded inside nvim, with `<leader>a*` keymaps wired (toggle, focus, send, accept/deny diff).
+
+This plugin doesn't ship those — it depends on them and ties them together with one agent and three skills.
+
+## Layout
+
+```
+nvim-agentic-companion/
+├── .claude-plugin/plugin.json    # manifest + userConfig (socket, config path)
+├── agents/
+│   └── companion.md              # the nvim-companion agent identity
+└── skills/
+    ├── editor-introspect/        # read live state via mcp__neovim__*
+    ├── editor-act/                # drive nvim safely (open, jump, toggle, run)
+    └── claude-code-handoff/       # delegate buffer edits to the in-editor Claude
+```
+
+## Agent
+
+`companion` — answers questions about the *running* nvim ("what's bound to `<leader>ff`?", "is lualine actually using catppuccin-mocha?") and acts on it ("open neovim.nix at the lualine block"). It reads the declarative NixVim config as the source-of-truth for *why* things are set up the way they are, and the live editor for *what is actually loaded right now*.
+
+## Skills
+
+- **`editor-introspect`** — read-only queries against the live nvim (keymaps, buffers, options, diagnostics, plugins, messages, cursor, selection).
+- **`editor-act`** — safe driving: open files, jump to definitions, trigger user keymaps, toggle UI. Does **not** edit buffer contents.
+- **`claude-code-handoff`** — when the work is "change code in this buffer," hand it to the in-editor Claude Code session so the user gets a diff to accept or reject inline.
+
+## Why split it three ways
+
+The companion's three jobs have different blast radii:
+
+- *Reads* are free; do them eagerly.
+- *Edits to navigation/UI* are cheap to undo; do them when asked.
+- *Edits to code* deserve a diff and human review; route them through the inner Claude that already has the right UX for that.
+
+The skills enforce that separation so the agent doesn't drift into running `nvim_buf_set_text` directly when it should be sending to the Claude Code split.
+
+## Configuration
+
+| Key             | Default                                                | Purpose                                                     |
+| --------------- | ------------------------------------------------------ | ----------------------------------------------------------- |
+| `nvim_socket`   | `/run/user/1000/nvim.sock`                             | Where the running nvim listens (must match the MCP server). |
+| `config_path`   | `/home/oleks/projects/servers/emmett/nixos/neovim.nix` | The declarative NixVim source the companion cites from.     |
+
+## License
+
+MIT.