feat: add agent/axon TUI screens and align list commands with pagination (#205)

## Summary
- Add agent list/detail TUI screens with private/public tabs, actions
popup, delete confirmation, and full cursor pagination
- Add axon list and axon detail TUI screens
- Rewrite CLI `agent list` and `axon list` to `.tsx` with TUI components
and standard pagination (`--limit`/`--starting-after`)
- Add `includeTotalCount` parameter to agent service for accurate
pagination totals
- Add axon service enhancements: search, `getAxon()`, `totalCount`
- Group Agents, Objects, and Axons under new "Agents & Objects" main
menu submenu
- Move Benchmarks menu item before Settings
- Rename "Storage Objects" to "Objects" throughout TUI (breadcrumbs,
labels, table titles)

Note: Agent routing, navigation store types, and
`getAgentColumns()`/`buildAgentTableColumns()` were introduced by #209
and are not part of this PR's diff.

## Test plan
- [x] `pnpm build` passes
- [x] Tests pass
- [x] Command docs auto-generated

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

Author: jason-rl