Motivation

When working with Google Docs through gog, there's no way to interact with comments from the docs command tree. While gog drive comments exists with full CRUD support, it's not discoverable when you're in a gog docs workflow, and it lacks some doc-specific conveniences like filtering resolved comments by default.

This PR adds gog docs comments as a doc-centric interface for managing comments, following the same pattern as docs export and docs copy which delegate to Drive API functionality.

What's New

A full gog docs comments command tree with 6 subcommands:

gog docs comments list <docId>              # List open comments (resolved filtered by default)
gog docs comments list <docId> --include-resolved  # Include resolved comments
gog docs comments get <docId> <commentId>   # Get a comment with full details + replies
gog docs comments add <docId> "text"        # Add a comment
gog docs comments add <docId> "text" --quoted "highlighted text"  # Anchor to text
gog docs comments reply <docId> <commentId> "reply text"  # Reply to a comment
gog docs comments resolve <docId> <commentId>  # Mark as done
gog docs comments resolve <docId> <commentId> -m "Fixed"  # Resolve with message
gog docs comments delete <docId> <commentId>  # Delete a comment

Key differences from drive comments

Example output

Plain text (default):

ID    AUTHOR   QUOTED                  CONTENT                    CREATED              RESOLVED  REPLIES
c1    Alice    The quick brown fox     Needs revision             2025-06-01 10:00     false     1
c3    Dave     Introduction section    Consider rewording this    2025-06-01 12:00     false     0

JSON (--json):

{
  "docId": "1BxiMVs0XRA...",
  "comments": [
    {
      "id": "c1",
      "author": {"displayName": "Alice"},
      "content": "Needs revision",
      "quotedFileContent": {"value": "The quick brown fox"},
      "createdTime": "2025-06-01T10:00:00Z",
      "resolved": false,
      "replies": [...]
    }
  ],
  "nextPageToken": ""
}

Implementation

• New file: internal/cmd/docs_comments.go — all 6 subcommands
• New file: internal/cmd/docs_comments_test.go — thorough tests
• Modified: internal/cmd/docs.go — added Comments field to DocsCmd

Patterns followed

• Uses shared helpers: collectAllPages, tableWriter, formatDateTime, truncateString, normalizeGoogleID, failEmptyExit, dryRunExit, confirmDestructive
• Same auth/token flow as all other commands
• Consistent output: --json for machine-readable, tabwriter for human-readable
• Pagination support: --max, --page, --all
• Validation follows same usage() pattern
• resolve uses Drive API reply with action: "resolve" per Google's docs

Tests

• Integration tests via Execute() covering JSON + plain text for all subcommands
• Resolved filtering tested: default (open only) vs --include-resolved
• Empty results handling
• Validation errors for all missing required arguments
• Unit tests for filterOpenComments including edge cases (nil, all open, all resolved)