fix: use find_dotenv(usecwd=True) for PyPI .env loading

load_dotenv() without usecwd=True fails for mcphub.exe because
find_dotenv() walks the call stack and searches from site-packages/
instead of the user's working directory. Bump to v3.0.4.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

pyproject.toml

@@ -1,6 +1,6 @@
 [project]
 name = "mcphub-server"
-version = "3.0.3"
+version = "3.0.4"
 description = "AI-native management hub for WordPress, WooCommerce, and self-hosted services via Model Context Protocol (MCP)"
 authors = [
     {name = "MCP Hub", email = "contact@mcphub.dev"}