Fix task restart, batch pause, runtime, and chat UI

Summary

This PR consolidates the earlier runtime, task, and UI fixes into one branch.

It supersedes:

• #155
• #156

Changes

• Run run.sh in background by default with HTTPS enabled, PID/log/status/stop/restart support, and startup password display.
• Keep conversation/project/WebShell conversation lists ordered by creation time instead of update time.
• Add conversation pagination first/last/jump controls.
• Add chat/task scroll-to-top and scroll-to-bottom controls.
• Repair interrupted manual task and batch queue states on startup.
• Make pausing a batch queue stop the active child task and leave later work pending.
• Add Windows terminal WebSocket fallback documentation and implementation.

Testing

• go test ./...
• git diff --check origin/main..HEAD
• Deployed to Kali and verified HTTPS startup.
• Frontend smoke tested in Chrome with normal task creation and slow batch queue pause behavior.