Move tests to repository root and update pytest configuration

- Move tests from src/gitea_mcp_remote/tests/ to tests/ (top-level)
- Update pytest.ini to point to new test location
- All imports already use absolute paths (gitea_mcp_remote.*)
- Tests run successfully from new location (28/30 pass, 2 pre-existing failures)

This improves project structure by following standard Python conventions
where tests live at the repository root level rather than inside the
source package.

Closes #21

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

tests/__init__.py

@@ -0,0 +1,9 @@
+"""Test suite for HTTP wrapper functionality."""
+
+# This package contains tests for:
+# - config: Configuration loader and validation
+# - filtering: Tool filtering for Claude Desktop compatibility
+# - middleware: HTTP authentication middleware
+# - server: Core HTTP MCP server (integration tests would go here)
+
+__all__ = []