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.

docs/RULES_FEATURE_SPEC.md

@@ -91,14 +91,16 @@ Dark theme throughout (near-black background, very dark green tint).
    *(OpenAppLock)* Time/Open Limit rules whose budget is spent for the day
    also appear here, blocked until midnight.
 3. **Usage** *(OpenAppLock addition — not in the Opal video)* — a section
-   directly below Blocked Apps showing live tracking for every enabled
-   Time/Open Limit rule scheduled today:
-   - Time Limit row: subtitle "18m of 45m used today", trailing "27m left";
-     when spent: "Blocked until tomorrow" (red).
-   - Open Limit row: subtitle "2 of 5 opens today", trailing "3 opens left";
-     when spent: "Blocked until tomorrow" (red).
-   Usage numbers come from the shared app-group ledger written by the
-   DeviceActivity monitor and shield-action extensions.
+   showing live tracking for every enabled Time/Open Limit rule scheduled today
+   **that is not currently blocking**. Each row leads its subtitle with the rule
+   **type** so the kind is clear without relying on the icon:
+   - Time Limit row: subtitle "Time Limit · 18m of 45m used today", trailing "27m left".
+   - Open Limit row: subtitle "Open Limit · 2 of 5 opens today", trailing "3 opens left".
+   A rule whose budget is **spent** (actively blocking) **moves out of Usage into
+   the "Currently Blocking" section** (it shows its type + usage there instead);
+   a *soft-unblocked* spent rule is paused (not blocking), so it returns to Usage
+   reading "Unblocked until tomorrow". Usage numbers come from the shared app-group
+   ledger written by the DeviceActivity monitor and shield-action extensions.
 3. **Rules** — header row: "Rules ›" (leading, tappable to a full list,
    presumably) and "**+ New**" (trailing, green tint) which opens the New Rule
    sheet.
@@ -514,11 +516,28 @@ Xh", "Xh left") is **derived**, not stored.
 OpenAppLock has since replaced the Opal-style custom presentation with the bare
 iOS design language, keeping the backend (models, logic, services), the
 flows, and the accessibility identifiers intact. Sections 1–5 remain as the
-reference for *what* the feature does; presentation now maps as follows:
+reference for *what* the feature does; presentation now maps as follows.
+
+After onboarding the app is a three-tab `TabView` (`MainTabView`), each tab its
+own `NavigationStack`:
+
+```
+TabView: [Home] [Rules] [Settings]
+   │        │        └── "Uninstall Protection" toggle + "Manage App Lists" ─▶ App List library (management mode)
+   │        └── rules grouped into Schedule / Time Limit / Open Limit sections; "+" ─▶ New Rule sheet
+   │                 └── tap a rule row ─▶ Rule Detail sheet ─▶ "Edit Rule" ─▶ Rule Editor
+   └── "Currently Blocking" section + "Usage" section
+```
+
+The app-level **enforcement lifecycle** (the `enforcer.refresh` 30 s loop, the
+rule-change reconcile, and a scene-active reconcile) lives on `MainTabView`, so
+it runs regardless of the selected tab.
 
 | Spec element | Native presentation |
 |---|---|
-| Apps home | `NavigationStack` + `List`; "Blocked Apps" and "Rules" sections; **rules are list rows** (kind icon, name, block summary, trailing live status — green when active); "+" toolbar button |
+| Home tab | `NavigationStack` + `List`. **"Currently Blocking"** section (renamed from "Blocked Apps") — the *rules* blocking right now: **no leading icon**; a Hard Mode rule shows a trailing `lock.fill` (the block can't be lifted), a soft rule shows a trailing "Unblock" button; tapping a hard row shows the "Hard Mode is on" alert, a soft row the unblock dialog. A limit rule whose budget is **spent** appears here (moved out of Usage) with a `<Type> · <usage>` subtitle. **"Usage"** section: every enabled limit rule scheduled today that is *not* currently blocking, each row a `<Type> · NN of MM used today` subtitle + trailing remaining/blocked label. |
+| Rules tab | `NavigationStack` + `List` split into **Schedule / Time Limit / Open Limit** sections (empty sections hidden); **rules are list rows** (leading kind icon, name, block summary, trailing live status — green when active); "+" toolbar button opens the New Rule sheet; tapping a row opens the Rule Detail sheet. |
+| Settings tab | `NavigationStack` + `Form`. **Uninstall Protection** toggle — while on, the device's app-removal is denied (`ManagedSettingsStore.application.denyAppRemoval`) whenever any Hard Mode rule is actively blocking. **Manage App Lists** pushes the shared App List library in management mode (create / edit / delete, honoring the Hard Mode lock — same flow as the rule editor's picker, minus selection). |
 | Rule detail | Sheet with inline nav title (name + "Schedule, 6h left" caption), `LabeledContent` rows, "Edit Rule" row pushes the editor; hard-locked rules show a lock row instead |
 | New Rule | `List` with a "Rule Type" section and preset sections as plain rows; editor pushed via `navigationDestination(item:)` |
 | Rule editor | Native `Form`: an inline **Name text field** at the top (no separate rename button; empty names fall back to the kind default), `DatePicker` rows, full-width day-circle row (≥44pt tap targets) with the summary in the section header, toggle rows with footers, stepper rows. Both modes commit via a **checkmark** in the navigation bar (labels: "Add Rule" / "Done"; replaces Hold to Commit). In edit mode an **ellipsis menu** ("Rule Actions") next to the checkmark holds Disable Rule and the destructive Delete Rule |
@@ -526,3 +545,22 @@ reference for *what* the feature does; presentation now maps as follows:
 
 Dropped custom components: `Theme`, `HoldToCommitButton`, `RuleCardView`,
 icon-pair/circle-button chrome.
+
+### 6.1 Uninstall Protection (Settings)
+
+A device-wide opt-in that makes Hard Mode harder to escape: while it is on **and**
+any Hard Mode rule is actively blocking, the user cannot delete apps from the
+device. `RulePolicy.shouldDenyAppRemoval(rules:enabled:usageFor:)` (= setting on
+AND any rule `isHardLocked`) is the single gate; `RuleEnforcer.refresh` applies it
+through `ShieldApplying.setAppRemovalDenied`, which sets
+`ManagedSettingsStore(named: "uninstall-protection").application.denyAppRemoval`
+(`true` to engage, `nil` to relinquish) on a **dedicated** store so per-rule
+shield clears never touch it. The setting persists in the app-group defaults
+(`uninstallProtectionEnabled`).
+
+Enforced on the **foreground path only** for v1 (launch + 30 s loop + rule change
++ scene-active). Known limitation: a Hard Mode window that *ends* while the app is
+closed leaves protection engaged until the app is next foregrounded — the safe
+failure direction for a locker. Background recompute in the monitor extension is a
+follow-up. Like all Screen Time behavior, the real device effect is only
+observable on a device (the simulator uses mock shields).