Simplify setup and settings with large Tailwind controls

[enaboapps]

Setup and settings now use larger controls and shorter labels, with advanced choices behind “More options”. Common tasks stay visible: add or test switches, choose a scanning method and speed, and connect a mobile device. Expanding or collapsing details preserves edits; errors reveal the affected section. Demonstrations show one short instruction with full explanations under “Read steps”.

Tailwind 4 provides shared 64 px minimum targets, 18 px control labels, 16 px supporting text and 12 px action spacing, without Preflight. Main-window zoom shortcuts are enabled, and the layout reflows at 200% zoom. The macOS minimum is 13.3. Protocols, persisted settings, application identity and native scanning overlays are unchanged.

Closes #850. Milestone: v1.0.0-rc.15.

Validation:

• Node 24: lint, 217 UI tests, 5 update-feed tests and production build pass.
• Rust 1.97.1: formatting, Clippy and 506 tests pass (one existing ignored test).
• Windows 11 ARM VM: built and ran the native app; visual checks covered light/dark themes, large controls, advanced disclosures, the 620×520 minimum window, 200% zoom and reachable setup dialog actions. Corrected cascade ordering and the old page minimum width during review/validation. The final small-text cleanup was rebuilt successfully in the VM.
• Independent review of latest head ac7ba87 found no actionable issues.
• Local installed application was not touched. All required CI checks pass, including macOS app/DMG packaging, Windows NSIS packaging, dependency auditing and CodeQL.