[Workflow][3/4] Add Grid View and Custom Reordering for Note Board

[Dyu20705]

Problem & Requirement

Provide a masonry/grid card layout on the Note Board alongside the existing list view, with card previews, tags, drawing thumbnails, and support for custom manual note sorting.

Architecture & Module Scope

• Target Files:
  • ui/list.js & ui/gridView.js
  • core/noteBoard.js
  • tests/e2e/grid-view.spec.mjs

Subtasks / Checklist

• Implement GridView component rendering responsive multi-column note cards.
• Add View Mode toggle (List vs Grid) in the board header, persisted in settings.
• Support keyboard arrow navigation across 2D grid cards.
• Render drawing projection thumbnails and task list progress directly on grid cards.
• Add E2E tests for grid layout, keyboard traversal, and view mode persistence.

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Parent Epic: #128 ([Epic] Workflow Refinement — Floating Editor Toolbar, Inspector Sidebar, and Board Views)
Priority: High

[Dyu20705]

Implemented via PR #154 and merged into dev.