Calendar commands fail with 404 in pure SA mode (getUserTimezone fetches CalendarList/primary)

[delight-ai-agent]

Problem

Calendar commands (e.g. gog calendar events <calendarId>) fail with 404 notFound when using a service account in pure SA mode (no impersonation).

The root cause is getUserTimezone() in internal/cmd/time_helpers.go:56, which unconditionally calls CalendarList.Get("primary") to resolve the user's timezone. A service account running in pure mode has no "primary" calendar, so the Google Calendar API returns 404.

This blocks all calendar commands that go through ResolveTimeRange → getUserTimezone.

Repro

# Set up pure SA mode (SA email matches --account)
gog auth service-account set --key=sa-key.json sa@project.iam.gserviceaccount.com

# Calendar shared with the SA has events, but this fails:
gog calendar events someone@example.com --account sa@project.iam.gserviceaccount.com
# → Google API error (404 notFound): Not Found

# Drive commands work fine in the same setup:
gog drive ls --parent <folderId> --account sa@project.iam.gserviceaccount.com
# → OK

Expected: Events listed from the shared calendar.

Actual: 404 notFound from CalendarList.Get("primary") before the actual events request is made.

Analysis

time_helpers.go:56:

func getUserTimezone(ctx context.Context, svc *calendar.Service) (*time.Location, error) {
    cal, err := svc.CalendarList.Get("primary").Context(ctx).Do()
    // ↑ SA has no primary calendar → 404

In impersonation mode (DWD), cfg.Subject is set so the API call runs as the impersonated user who does have a primary calendar. In pure SA mode (introduced in PR #1), no impersonation occurs, so CalendarList.Get("primary") has no user context.

Possible fix

When CalendarList.Get("primary") fails in pure SA mode, fall back to:

1. The timezone of the explicitly specified calendarId (via CalendarList.Get(calendarId)), or
2. UTC

✍️ Author: Claude Code with @carrotRakko (AI-written, human-approved)