[StanleyLl0yd]

First focused screenshot-driven UI fix for #156.

Evidence: in user-supplied v0.2.0 Russian/dark screenshot at a large window, DiskInfoBar's capacity 228.3 GB wraps and actions are displayed as Показать в Fi…, Скопировать п…, Переместить в…. The restricted-access description has insufficient contrast.

Changes:

• Stack target header and the disk information bar rather than forcing them into a single competing horizontal row; keep capacity/free values atomic on a single line, and place the usage bar on its own line.
• Move selected-item action buttons into a dedicated row, keep localized labels untruncated at macOS minimum 800-pixel width; bound a long path to two lines with middle truncation and full path available through Help/text selection.
• Use semantic primary/secondary text and the semantic warning icon on restricted-access information; improve readability without weakening access guidance.

No filesystem/scan, data sizing, Trash semantics, entitlements, dependencies, versions, release or app icon changes. v0.2.0 remains immutable. This PR is limited to ContentView.swift.

Verify macOS CI/Debug XCTest/Release build, Security, Dependency Review, CodeQL Swift+Actions and review threads against exact head. Follow with real-Mac screenshot acceptance (RU/EN, dark/light, 800×600 and larger). Avoid claiming that simulator/CI alone verifies actual rendered typography.