Summary

Adds three new subcommands for managing tabs/sheets within a spreadsheet, using the Sheets API batchUpdate endpoint:

• gog sheets add-tab <spreadsheetId> <tabName> — Create a new tab/sheet
• gog sheets rename-tab <spreadsheetId> <oldName> <newName> — Rename an existing tab
• gog sheets delete-tab <spreadsheetId> <tabName> — Delete a tab (requires --force or interactive confirmation)

Motivation

The existing sheets commands support reading/writing cell data (get, update, append, clear), formatting (format), inserting rows/columns (insert), and creating spreadsheets (create), but there is no way to manage the tabs themselves within an existing spreadsheet. This is a common need when programmatically building multi-tab spreadsheets.

Implementation

Uses BatchUpdateSpreadsheetRequest with:

• AddSheetRequest for add-tab
• UpdateSheetPropertiesRequest (fields: title) for rename-tab
• DeleteSheetRequest for delete-tab

Follows the same patterns as sheets insert (PR #203) — uses fetchSheetIDMap for tab name → sheet ID resolution, confirmDestructive for delete safety, and supports --json output and --dry-run.

Usage

# Add a new tab
gog sheets add-tab 1BxiMVs0XRA5nFMdKvBdBZjgmUUqptlbs74OgVE2upms "Q1 Data"

# Rename a tab
gog sheets rename-tab 1BxiMVs0XRA5nFMdKvBdBZjgmUUqptlbs74OgVE2upms "Sheet1" "Summary"

# Delete a tab (with confirmation)
gog sheets delete-tab 1BxiMVs0XRA5nFMdKvBdBZjgmUUqptlbs74OgVE2upms "Old Data"

# Delete without confirmation
gog sheets delete-tab --force 1BxiMVs0XRA5nFMdKvBdBZjgmUUqptlbs74OgVE2upms "Old Data"

Testing

• 5 unit tests with httptest mock server covering:
  • add-tab — verifies AddSheet request with correct title
  • rename-tab — verifies UpdateSheetProperties with correct sheet ID, title, and fields mask
  • delete-tab --force — verifies DeleteSheet with correct sheet ID
  • rename-tab unknown tab — error handling
  • delete-tab unknown tab — error handling
• Note: existing contacts_crud.go has pre-existing type errors on main that prevent full go build ./...; this PR does not touch that file

New files