feat: re-skin to native three-tab UI and add Uninstall Protection

Replace the custom themed presentation with the bare native iOS design
language across a three-tab TabView (Home / Rules / Settings):

- MainTabView hosts the enforcement lifecycle (refresh loop, rule-change
  and scene-active reconcile) so it runs regardless of the selected tab
- HomeView: "Currently Blocking" + "Usage" sections (replaces AppsHomeView)
- RulesListView: rules grouped into Schedule / Time Limit / Open Limit
- SettingsView: Uninstall Protection toggle + Manage App Lists
- AppListLibraryView / ManageAppListsView: shared App List management
- AppSettings: app-group-backed settings store

Uninstall Protection: while enabled and any Hard Mode rule is actively
blocking, deny device app-removal via a dedicated ManagedSettingsStore
(RulePolicy.shouldDenyAppRemoval -> RuleEnforcer -> ShieldController).

Slim AppListPickerSheet to the picker role; drop AppsHomeView and the
custom Theme/HoldToCommitButton/RuleCardView chrome. Update spec section 6
and the unit/UI test suites accordingly.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

OpenAppLockTests/UsageTests.swift

@@ -254,4 +254,14 @@ struct UsageDisplayTests {
         let over = RuleUsage(minutesUsed: 60)
         #expect(UsageDisplay.subtitle(for: timeRule, usage: over) == "45m of 45m used today")
     }
+
+    @Test("Typed subtitles prefix the rule kind so type is clear without the icon")
+    func typedSubtitles() {
+        #expect(
+            UsageDisplay.typedSubtitle(for: timeRule, usage: RuleUsage(minutesUsed: 18))
+                == "Time Limit · 18m of 45m used today")
+        #expect(
+            UsageDisplay.typedSubtitle(for: openRule, usage: RuleUsage(opensUsed: 2))
+                == "Open Limit · 2 of 5 opens today")
+    }
 }