feat(cfl): port space list pagination cursor

[rianjs]

Port pagination cursor support from confluence-cli PR #105.

Files to modify:

• tools/cfl/internal/cmd/space/list.go - Add --cursor flag
• tools/cfl/internal/cmd/space/list_test.go - Add tests

Features:

• Add --cursor flag for cursor-based pagination
• Display cursor value for next page when more results available
• Extract cursor from _links.next URL

Usage:

cfl space list                              # First page
cfl space list --cursor "eyJpZCI6MTIzfQ=="  # Next page
cfl space list --limit 100                  # Larger page

Source: open-cli-collective/confluence-cli#105

[rianjs]

Implementation Plan

1. Add cursor to listOptions struct - Add cursor string field
2. Add --cursor flag - cmd.Flags().StringVar(&opts.cursor, "cursor", "", "Pagination cursor for next page")
3. Pass cursor to API - Set apiOpts.Cursor = opts.cursor
4. Extract and display next cursor - Parse cursor from _links.next URL query param and show it to users when HasMore() is true
5. Add tests - Test cursor is passed to API, test cursor extraction and display

The API layer already supports cursor (ListSpacesOptions.Cursor) - this just exposes it in the CLI.