Initial commit: AYON Matrix Publish addon

- package.py: addon manifest (v0.1.0)
- server/__init__.py: BaseServerAddon definition
- server/ayon_matrix_publish/plugins/publish/integrate_matrix.py:
  Pyblish plugin that uploads published representations to Matrix
  rooms during the Integration stage. Supports:
  - Upload to Matrix content repository (mxc:// URI)
  - Formatted messages with preview images
  - Auto room creation per asset
  - Configurable via Studio Settings or env vars
- create_package.py: builds distributable .zip package

create_package.py

@@ -0,0 +1,51 @@
+#!/usr/bin/env python3
+"""Create an AYON addon .zip package for distribution."""
+
+import os
+import sys
+import zipfile
+from pathlib import Path
+
+
+def create_package():
+    root = Path(__file__).parent
+
+    # Read version
+    version_file = root / "server" / "ayon_matrix_publish" / "version.py"
+    version = "0.1.0"
+    if version_file.exists():
+        exec(version_file.read_text(), {}, {})
+        version = locals().get("__version__", version)
+
+    package_name = f"matrix_publish-{version}.zip"
+    package_path = root / package_name
+
+    print(f"Creating {package_name}...")
+
+    with zipfile.ZipFile(package_path, "w", zipfile.ZIP_DEFLATED) as zf:
+        # Add package.py
+        zf.write(root / "package.py", "package.py")
+
+        # Add server files
+        server_dir = root / "server"
+        for file_path in server_dir.rglob("*"):
+            if file_path.is_file() and "__pycache__" not in str(file_path):
+                arcname = str(file_path.relative_to(root))
+                zf.write(file_path, arcname)
+                print(f"  + {arcname}")
+
+        # Add client files
+        client_dir = root / "client"
+        if client_dir.exists():
+            for file_path in client_dir.rglob("*"):
+                if file_path.is_file() and "__pycache__" not in str(file_path):
+                    arcname = str(file_path.relative_to(root))
+                    zf.write(file_path, arcname)
+                    print(f"  + {arcname}")
+
+    print(f"\nPackage created: {package_path}")
+    print(f"Size: {package_path.stat().st_size / 1024:.1f} KB")
+
+
+if __name__ == "__main__":
+    create_package()