refactor(tooltips): extract native paired tooltip host

docs/ARCHITECTURE.md

@@ -120,6 +120,8 @@ Settings-dock rows themselves are data: every cycling or boolean row is a `Cycli
 
 `TooltipPreviewModePolicy` owns preview priority. Upgrade hotkey wins first, then enchant hotkey, then enchant `Always`, then enchant `AutoOnPedestalChoice` only when the current choice pedestal is an enchant pedestal (`src/BazaarPlusPlus/Game/Tooltips/TooltipPreviewModePolicy.cs:52-74`). A `TooltipModifierRefreshController` mountable re-resolves open preview tooltips when the Ctrl/Shift hold state changes; both ordinary game cards and hovered synthetic previews keep the existing native tooltip controller alive, replace its `CardTooltipData` through `ApplyPreviewTooltip`, and synchronously settle layout behind a temporary visibility gate instead of replaying native hide/show positioning and fades (`src/BazaarPlusPlus/Game/Tooltips/TooltipModifierRefreshController.cs:110-173`, `src/BazaarPlusPlus/Game/Tooltips/TooltipPreviewContentRefresh.cs:12-65`, `src/BazaarPlusPlus/GameInterop/Tooltips/NativeCardTooltipContentRefresher.cs:12-52`). The tooltip patch surface also covers encounter/event tooltips (gated by the `Game/EventPreview` settings toggle), quest reward previews and aggregate-item missing types (separate implementations sharing the default-off `QuestPreview/Enabled` gate), and hero level rewards (`src/BazaarPlusPlus/Patches/Tooltips/`). Disabling Quest Preview immediately restores tracked native quest text/layout and hides its pooled aggregate-item sections. Mod-appended text is rendered through the shared `BppTooltipSections` helper. Sections keep the cloned native donor typography and attach the game's own zh-CN fallback chain only when BPP-authored content contains CJK (`src/BazaarPlusPlus/Patches/Tooltips/BppTooltipSections.cs:12-15`, `src/BazaarPlusPlus/Patches/Tooltips/BppTooltipSections.cs:55-76`).
 
+`GameInterop/Tooltips` holds two unrelated native-tooltip adapters that must not be merged. `NativeCardTooltipContentRefresher` replaces the `CardTooltipData` of an already-visible primary tooltip and settles its layout (`src/BazaarPlusPlus/GameInterop/Tooltips/NativeCardTooltipContentRefresher.cs:12-52`). `NativePairedTooltipHost` owns the separate "custom content inside the native auxiliary tooltip, pinned beside the native card tooltip" presentation: native state capture/restore, the `CanvasGroupGate` visibility gates, the cloned native background, the paired fade, side selection, and coordinate conversion (`src/BazaarPlusPlus/GameInterop/Tooltips/NativePairedTooltipHost.cs`). Composition creates one plugin-lifetime host; it is not `IDisposable`, and the releasable unit is the `NativePairedTooltipSession` a feature acquires from it (`src/BazaarPlusPlus/BppComposition.cs:237-252`). The host reports placement outcomes through `PlacementResult` and never logs: reason codes, their once-only latches, and native show/hide arbitration stay with the consuming feature, because that latch behavior decides how many records reach the log. The host also does not arbitrate the native auxiliary singleton — other code drives it directly (`src/BazaarPlusPlus/Game/CombatReplay/CurrentReplayRecordingButtonController.cs:257-261`), so a single active session serializes only this host's own usage. Purely geometric decisions are the unit-tested `NativePairedTooltipPlacementMath`; the shared `NativePairedTooltipMetrics.Epsilon` deliberately serves both as a geometry tolerance and as the CanvasGroup alpha interactivity threshold. Combat Impact is currently the only consumer, and it supplies its own trim strategy through `IPairedContentBudget` (`src/BazaarPlusPlus/Patches/PostCombatImpact/NativePostCombatImpactTooltipView.cs`). `NativePairedTooltipArchitectureTests` ratchets the plumbing into this module.
+
 BPP hotkeys are user-rebindable and persisted in config per action. `BppHotkeyActionId` covers five actions: the two hold-preview hotkeys (Ctrl enchant / Shift upgrade defaults) plus toggles for CollectionPanel, LiveBuildPanel, and HistoryPanel (`src/BazaarPlusPlus/Game/Input/BppHotkeyActionId.cs`); rebinding rows are cloned from native settings rows (`src/BazaarPlusPlus/Game/Input/BppKeyBindRowController.cs`), and panel toggle presses are resolved per frame by the Overlay Panel Host. Binding-path normalization, ctrl/shift alias expansion, conflict detection, and the default/display data tables are the pure `HotkeyBindingPathCore` (`src/BazaarPlusPlus/Game/Input/HotkeyBindingPathCore.cs`, compile-linked into the zero-ManagedPath `tests/HotkeyBindingPath.Tests/`); `BppHotkeyService` remains the Unity/config facade. Binding paths in `BazaarPlusPlus.cfg` `[Hotkeys]` are untrusted input: junk normalizes to empty and falls back to the action default. The conflict check compares BPP actions only against other BPP actions, not native `Gameplay/*` bindings.
 
 The settings dock registers all feature rows through `SettingsDockEntryRegistry` with order constants centralized in `BppSettingsDockOrder` (`src/BazaarPlusPlus/Game/Settings/BppSettingsDockOrder.cs`); the roster spans history, name override, bilingual item names, legendary position, enchant preview, event and quest previews, combat status bar, Chinese locale, supporter list, voice subtitles, end-of-run screenshot, and BazaarDB upload (`src/BazaarPlusPlus/BppComposition.cs:162-180`). There is no BPP font selector because all BPP-owned game UI follows the game's font assets.