I had trouble running the delefated_access example project where I was getting dependency errors:

uv run python main.py
error: Failed to generate package metadata for `keycardai-mcp-fastmcp @ editable+../../`
  Caused by: Failed to parse entry: `keycardai-oauth`
  Caused by: `keycardai-oauth` references a workspace in `tool.uv.sources` (e.g., `keycardai-oauth = { workspace = true }`), but is not a workspace member

This remove the local [tool.uv.sources] override in pyproject.toml so the example resolves keycardai-mcp-fastmcp from the published package by default (with docs on how to run against local source via the workspace).

Also tweaks the environment variable handling to support KEYCARD_ZONE_URL in addition to KEYCARD_ZONE_ID using the default env var handling from the library.