Add cursor-based pagination support

[iamfj]

Problem

The --limit option only fetches the first N items. Pagination via cursor (after/before) is not supported, preventing users from iterating through large datasets.

Current State

• issues list only accepts --limit parameter
• GraphQL queries use only first argument
• No after, before, or cursor support
• Users cannot access results beyond the limit

Expected State

Support cursor-based pagination following Linear GraphQL API specification:

• --limit for result count (uses first)
• --after <cursor> to fetch next page
• --before <cursor> to fetch previous page
• Response should include pageInfo with hasNextPage, hasPreviousPage, and edge cursors

Impact

• Users with >50 issues cannot browse beyond default/specified limit
• Automation scripts cannot reliably paginate through results
• API inconsistency vs. Linear GraphQL capabilities

Technical Notes

• Requires updates to GraphQL queries to include after, before parameters and pageInfo fields
• Service layer needs to accept and pass pagination parameters
• CLI commands need new options for --after and --before