auth.deliver changes from as:file to as:env:
- Gmail: GMAIL_CREDS_JSON env var (Google authorized_user JSON)
- Gcal: GCAL_CREDS_JSON env var
mcp_config.env removed entirely — Skald injects the env var at runtime,
no path on disk needed.
Server scripts updated:
- Check GMAIL_CREDS_JSON / GCAL_CREDS_JSON env var first
- Use Credentials.from_authorized_user_info() instead of
from_authorized_user_file()
- Fall back to file-based loading for standalone/legacy use
- _persist_creds only writes to disk when _creds_path is set
gcal/verify.py: support GCAL_CREDS_JSON env var with shared _check_api()
Docs (SKALD.md): updated examples, field table, connector table.