v0.3: PySide2 mini-UI panel + installer

- New: hermes_bridge_panel.py — PySide2 floating panel with:
  - Port configuration (spinner)
  - Open/Close toggle with green/red status
  - Auto-detected hostname
  - One-click copy prompt: 'Hey Hermes, I have Houdini on [host] port [N]'
  - Persists port setting across sessions
- New: install.py — auto-detects houdini dir, copies panel + shelf
- New: hermes_bridge.shelf — shelf tool integration
- Updated: README with panel usage instructions

README.md

@@ -17,13 +17,26 @@ No custom server needed — uses Houdini's built-in `openport` + `hcommand` prot
 
 ## Quick Start
 
-### 1. Install the Shelf Tool (once)
+### 1. Install (once)
 
-Copy `houdini/shelf/hermes_bridge.shelf` to your Houdini toolbar, or run the shelf script directly in Houdini's Python Shell.
+```bash
+cd houdini && python3 install.py
+```
 
-### 2. Open the Bridge (every session)
+Or manually: copy `hermes_bridge_panel.py` to `~/houdini21.0/scripts/python/`.
 
-Click the **Hermes Bridge** shelf button in Houdini. It opens port 12345 and shows a status dialog.
+### 2. Open the Panel (every session)
+
+In Houdini Python Shell (`Alt+Shift+P`):
+```python
+exec(open(hou.homeHoudiniDirectory() + '/scripts/python/hermes_bridge_panel.py').read())
+show()
+```
+
+The panel lets you:
+- Choose a port number
+- Open/Close the bridge with one click
+- Copy a ready-to-use prompt: *"Hey Hermes, I have a Houdini session running on [hostname] (port 12345)"*
 
 ### 3. Use from Hermes