fix(ui): improve responsive layout for modals, dropdowns and cards (#106)

[Lexus2016]

Summary

Addresses #106 by improving UI layout responsiveness on mobile devices and narrow viewports:

• Modals: Constrains .dir-modal and .ssh-host-modal to max-width: calc(100vw - 24px). In mobile media queries (@media (max-width: 800px)), overrides strict desktop constraints on #cfgModal .modal to ensure modal dialogs fit within the viewport without horizontal overflow.
• Kanban on Mobile/Tablet: In public/kanban.html, adjusts .proj-dd-btn width, allows card actions to wrap gracefully with flex-wrap: wrap, and adapts modals as bottom sheet on small viewports (@media (max-width: 480px)).
• Tooltips for Truncated Text: Adds title attributes with full project name to project dropdown buttons when text is truncated.
• Automated Tests: Adds test/responsive-ui.test.js validating responsive constraints across index.html and kanban.html.

Closes #106