feat: initial nix package and NixOS module for hermes-agent v0.2.0

- buildPythonApplication with Python 3.12
- All extras included (messaging, cron, tts, voice, mcp, honcho, acp)
- Custom PyPI packages: fal-client, honcho-ai, agent-client-protocol
- NixOS module with systemd service for gateway mode
- Runtime deps wrapped: nodejs 22, ripgrep, ffmpeg, git
- Flake-based with overlay support

README.md

@@ -0,0 +1,75 @@
+# nix-hermes
+
+Nix package and NixOS module for [Hermes Agent](https://github.com/NousResearch/hermes-agent) by Nous Research.
+
+## Quick Start
+
+### Flake usage
+
+```nix
+{
+  inputs.nix-hermes.url = "github:0xrsydn/nix-hermes";
+
+  outputs = { self, nixpkgs, nix-hermes, ... }: {
+    nixosConfigurations.myhost = nixpkgs.lib.nixosSystem {
+      modules = [
+        nix-hermes.nixosModules.hermes-agent
+        {
+          services.hermes-agent = {
+            enable = true;
+            environmentFile = "/run/secrets/hermes-env";  # API keys
+          };
+        }
+      ];
+    };
+  };
+}
+```
+
+### Just the package
+
+```bash
+nix run github:0xrsydn/nix-hermes -- --help
+```
+
+### NixOS module options
+
+| Option | Type | Default | Description |
+|--------|------|---------|-------------|
+| `enable` | bool | `false` | Enable the Hermes Agent gateway service |
+| `user` | string | `"hermes"` | Service user |
+| `group` | string | `"hermes"` | Service group |
+| `homeDir` | path | `/var/lib/hermes` | State directory |
+| `workDir` | path | `${homeDir}/workspace` | Working directory |
+| `environmentFile` | path | `null` | Secrets file (API keys, tokens) |
+| `extraEnvironment` | attrs | `{}` | Extra env vars |
+| `extraArgs` | list | `[]` | Extra CLI args for `hermes gateway` |
+| `extraPackages` | list | `[]` | Extra packages on PATH |
+
+### Environment file example
+
+```bash
+ANTHROPIC_API_KEY=sk-ant-...
+OPENROUTER_API_KEY=sk-or-...
+TELEGRAM_TOKEN=123456:ABC...
+OPENAI_API_KEY=sk-...
+```
+
+## What's included
+
+- **`hermes`** — Interactive CLI
+- **`hermes-agent`** — Agent runner
+- **`hermes-acp`** — ACP adapter
+- **NixOS module** — systemd service for gateway mode
+- Runtime deps wrapped: Node.js 22, ripgrep, ffmpeg, git
+
+## Development
+
+```bash
+nix develop  # Enter dev shell with hermes on PATH
+nix build    # Build the package
+```
+
+## License
+
+MIT (same as upstream)