v0.4: Official Houdini package system integration

- hermes_houdini_bridge.json: package descriptor (generated by install.sh)
- scripts/python/hermes_bridge_panel.py: moved to package-standard location
- python_panels/hermes_bridge.pypanel: registered in Windows menu
- install.sh: one-command installer (generates JSON with correct path)
- git clone + install.sh = fully installed; git pull = update
- Panel opens via Windows -> Hermes Bridge (no Python Shell needed)

python_panels/hermes_bridge.pypanel

@@ -0,0 +1,6 @@
+{
+    "interface": "hermes_bridge_panel.show",
+    "label": "Hermes Bridge",
+    "icon": "MISC_python",
+    "help_url": "https://git.niklashmotion.art/Hermes/hermes-houdini-bridge"
+}