Aggregate usage limits at group level for App + Keyword blockers and surface remaining minutes in group lists

[Copilot]

Usage based groups were effectively granting per app budgets instead of enforcing a shared group budget. This updates both App Blocker and Keyword Blocker to evaluate limits against aggregated group usage, and exposes remaining minutes directly in group list rows.

• Behavior fix: App Blocker usage groups

  • Switched usage evaluation from current package usage to sum(usage of all packages in the group).
  • Introduced per package mapping to its full usage group context so any app in the group enforces the same shared budget.

• Behavior fix: Keyword Blocker usage groups

  • Removed package scoped usage checks for usage mode.
  • Usage limit and next recheck calculations now use total matched website usage across the entire keyword group for the day.

• UI: group list visibility of remaining budget

  • App groups list now appends Remaining today: X mins for usage based groups.
  • Keyword groups list now appends the same Remaining today: X mins for usage based groups.
  • Remaining minutes are computed from group limit - aggregated group usage.

// Before (effective per-app budget)
val currentUsage = usageStats.firstOrNull { it.packageName == packageName }?.totalTime ?: 0L

// After (shared group budget)
val currentUsage = usageStats
    .filter { usageGroupConfig.groupPackages.contains(it.packageName) }
    .sumOf { it.totalTime }