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.

OpenAppLockUITests/AppListUITests.swift

@@ -6,7 +6,8 @@
 import XCTest
 
 /// App lists: the editor's App List row, the picker (select / create / edit),
-/// rule-level Block vs Allow Only, and the Hard Mode list lockdown.
+/// rule-level Block vs Allow Only, and the Hard Mode list lockdown. The rule
+/// editor (and its app-list picker) is reached from the Rules tab.
 final class AppListUITests: XCTestCase {
     override func setUpWithError() throws {
         continueAfterFailure = false
@@ -14,6 +15,7 @@ final class AppListUITests: XCTestCase {
 
     func testScheduleEditorOffersModeChoice() throws {
         let app = XCUIApplication.launchOpenAppLock()
+        app.goToRulesTab()
         app.buttons["newRuleButton"].waitToAppear().tap()
         app.buttons["ruleKind-schedule"].waitToAppear().tap()
 
@@ -25,6 +27,7 @@ final class AppListUITests: XCTestCase {
 
     func testLimitEditorsAreBlockOnly() throws {
         let app = XCUIApplication.launchOpenAppLock()
+        app.goToRulesTab()
         app.buttons["newRuleButton"].waitToAppear().tap()
 
         app.buttons["ruleKind-timeLimit"].waitToAppear().tap()
@@ -46,6 +49,7 @@ final class AppListUITests: XCTestCase {
 
     func testCreateAppListFlowSelectsNewList() throws {
         let app = XCUIApplication.launchOpenAppLock()
+        app.goToRulesTab()
         app.buttons["newRuleButton"].waitToAppear().tap()
         app.buttons["ruleKind-timeLimit"].waitToAppear().tap()
 
@@ -79,6 +83,7 @@ final class AppListUITests: XCTestCase {
 
     func testDetailShowsAppListName() throws {
         let app = XCUIApplication.launchOpenAppLock(seedScenario: "standard")
+        app.goToRulesTab()
         app.buttons["ruleCard-Work Time"].waitToAppear().tap()
 
         let row = app.element("detailRow-Block").waitToAppear()
@@ -87,6 +92,7 @@ final class AppListUITests: XCTestCase {
 
     func testHardModeSessionLocksAppListEditing() throws {
         let app = XCUIApplication.launchOpenAppLock(seedScenario: "hard-mode-active")
+        app.goToRulesTab()
 
         // "Sleep" is soft and editable even while "Locked In" hard-blocks.
         app.buttons["ruleCard-Sleep"].waitToAppear().tap()
@@ -103,6 +109,7 @@ final class AppListUITests: XCTestCase {
 
     func testAppListsEditableWithoutHardSession() throws {
         let app = XCUIApplication.launchOpenAppLock(seedScenario: "standard")
+        app.goToRulesTab()
 
         app.buttons["ruleCard-Sleep"].waitToAppear().tap()
         app.buttons["editRuleButton"].waitToAppear().tap()