feat: drag to reorder rules

[Ravian18]

Summary

• Adds drag-to-reorder for entries in the Rules tab via .onMove, mirroring the existing pattern in BrowsersTab. Order is persisted through @AppStorage("rules") and directly controls evaluation priority (first match wins in BrowserinoApp.handleURLs).
• Drive-by fix: removes a call to scrollEdgeEffectDisabled(_:for:) in View+ScrollEdgeDisabled.swift that does not exist in the public SwiftUI API of the macOS 26.4 SDK (Xcode 26.4), which currently breaks the build on main.

Test plan

• Build succeeds on Xcode 26.4 / macOS 26.4
• Rules can be dragged up/down in Preferences → Rules
• New order persists across Preferences close/reopen and app relaunch
• A reordered specific rule correctly shadows/unshadows a broad rule when opening matching URLs
• The "Add new rule" row cannot be dragged or displaced