feat: collapsible icon-only Host Inspector sidebar, resizable divider

[Atreus-X]

Summary

• Host Inspector sidebar (Overview, Network, Ports, Processes, Services, Docker) can be collapsed to an icon-only rail with a toggle at its top, and expanded again.
• Collapsed icons show a hover tooltip (section name, badge count, "changed since baseline"); a changed section keeps a dot on its icon.
• The divider between the sidebar and the content can be dragged to resize the sidebar (120-360px); double-click resets to the default width.

Notes

• UI only: it does not touch the data path, so SSH (SFTP / tmux / exec) and wsh hosts behave the same. No wsh dependency added.
• Collapsed state and width are remembered across restarts (localStorage, one shared preference for all Host Inspector blocks; falls back to defaults if unavailable).
• Branched from main. It edits hostinfo.tsx near fix(hostinfo): a narrow Host Inspector scrolls sideways #43 (fix/hostinfo-hscroll), which changes the root and SectionBody lines; expect a small textual conflict if merged after fix(hostinfo): a narrow Host Inspector scrolls sideways #43, keep both sides.

Test plan

• npx tsc --noEmit: no new errors in the touched files
• npx vitest run: 104 passed
• Rendered the collapsed rail in the preview server
• Toggle collapse/expand; tooltips appear on hover in collapsed mode
• Drag the divider; double-click resets; width is clamped
• Collapse/resize, restart: the sidebar comes back the same
• Section switching and badges still work in both modes

🤖 Generated with Claude Code

https://claude.ai/code/session_01W6QMXXvRReaKxWk1JL5Et6