Update list_tickets MCP tool to add pagination with max limit of 20

## Task Description The `list_tasks` MCP tool currently returns all tickets at once, which can exceed token limits (145,369 characters). Add pagination to return results in manageable chunks. ## Changes Required 1. Modify `list_tasks` to accept `offset` parameter (default: 0) 2. Change default `limit` from current value to 20 (max: 20) 3. Return `total_count` in response so callers know pagination info 4. Update response format to include pagination metadata ## Example Response Format ```json { "tickets": [...], // Array of tickets (max 20) "total_count": 150, // Total number of tickets "offset": 0, // Current offset "limit": 20, // Current limit "has_more": true // Whether more pages exist } ``` ## Files to Modify - `app/handlers/tinker_worker_handler.rb` (or similar handler file) - `app/handlers/tinker_reviewer_handler.rb` - `app/handlers/tinker_orchestrator_handler.rb`