test: add comprehensive list/get command coverage (unit + integration)

- tests/unit/list-table-formatting.test.ts: 18 unit tests for Key-column
  fallback and field-formatting logic in process-definitions, user-tasks,
  incidents, and jobs list commands (mirrors process-instances.test.ts pattern)

- tests/integration/list-commands.test.ts: all list and get CLI commands
  tested via spawnSync with every flag combination:
  list pi  — --id / --state / --all / --sortBy+--asc/--desc / --limit
             / --between / --dateField / text header check
  list pd  — --sortBy+--asc/--desc / --limit / text header check
  list ut  — --state / --all / --sortBy+--asc/--desc / --limit / text headers
  list inc — --state / --processInstanceKey / --sortBy+--asc/--desc
             / --limit / text headers
  list jobs — --state / --type / --sortBy+--asc/--desc / --limit
              / --between (8.9+ skip) / text headers
  get pi   — plain + --variables
  get pd   — plain + --xml
  get inc  — plain
  search pi/ut/inc/jobs/variables — CLI surface + sort flags
  Function-level tests for listProcessDefinitions, getProcessDefinition,
  listUserTasks, listIncidents, getIncident, listJobs using console.log
  capture to verify actual output content

Co-authored-by: vobu <6573426+vobu@users.noreply.github.com>

Author: Copilot