feat: convert to pip package

- Restructure repo into hermes_identity_plugin/ Python package
- Add pyproject.toml with setuptools build config
- Register identity entry point under hermes_agent.plugins
- Include plugin.yaml, .json, .yaml as package data
- Update README with pip install instructions and project layout

README.md

@@ -46,11 +46,29 @@ initialization — no files are changed on disk.
 4. **Missing config or env** → returns None → Honcho behaves exactly as
    before (creates `user-default-*` peers — safe fallback).
 
-## Installation
+## Project layout
+
+```
+hermes-identity-plugin/
+├── pyproject.toml              # pip package config
+├── README.md
+├── hermes_identity_plugin/     # Python package
+│   ├── __init__.py             # register() entry point
+│   └── plugin.yaml             # Hermes plugin metadata
+├── config.sample.json
+└── docs/
+    ├── enforcement.md
+    └── how-it-works.md
+```
+
+### Option 1: pip package (recommended)
 
 ```bash
-# 1. Install the plugin from Gitea
-hermes plugins install ssh://git@code.lazyworkhorse.net:2222/Hermes/hermes-identity-plugin.git
+# Install from Gitea (requires GITEA_PAT in environment)
+pip install git+https://gortium:${GITEA_PAT}@code.lazyworkhorse.net/gortium/hermes-identity-plugin.git
+
+# Or install from local checkout
+pip install /path/to/hermes-identity-plugin
 
 # 2. Create the config file (persistent volume)
 cp config.sample.json /opt/data/identity-config.json
@@ -59,6 +77,12 @@ cp config.sample.json /opt/data/identity-config.json
 # 4. Restart gateways to pick up the plugin
 ```
 
+### Option 2: Legacy plugin install
+
+```bash
+hermes plugins install ssh://git@code.lazyworkhorse.net:2222/gortium/hermes-identity-plugin.git
+```
+
 ## Config file: `/opt/data/identity-config.json`
 
 ```json