Refactored the application's multi-tab navigation to strictly align with the official AndroidX `nav3-recipes` for multiple backstacks.
Previously, swapping a single `NavBackStack` list instance caused Navigation 3 to perceive old entries as "popped," leading to the destruction of their associated `ViewModelStore` and UI state.
This commit resolves the issue by:
- Redesigning `MultiBackstack` as a state holder managing independent `NavBackStack` instances per tab.
- Modifying `MeshtasticNavDisplay` to bind a fresh set of decorators (specifically `SaveableStateHolderNavEntryDecorator` and `ViewModelStoreNavEntryDecorator`) to the active backstack dynamically via `remember(backStack)`. This ensures decorators are swapped alongside the stack, preserving state for inactive tabs.
- Implementing the standard "exit through home" back-handling pattern across all platforms.
- Removing legacy manual string keys from `koinViewModel()` injections, as `ViewModelStoreNavEntryDecorator` now correctly isolates ViewModel scope per entry.
- Added `androidx.lifecycle.viewmodel.navigation3` dependencies to the `app` and `desktop` root modules to support the decorator injections at the root composition level.
- Replace the custom `AdaptiveListDetailScaffold` with the official `ListDetailSceneStrategy` to manage adaptive layout orchestration.
- Integrate `ListDetailSceneStrategy` into `MeshtasticNavDisplay` to enable native pane switching based on the navigation backstack.
- Update `ContactsNavigation` and `NodesNavigation` graphs to include `listPane()` and `detailPane()` metadata for relevant route entries.
- Simplify `AdaptiveContactsScreen` and `AdaptiveNodeListScreen` by removing manual scaffold navigation logic and delegating to the navigation framework.
- Add the `jetbrains.compose.material3.adaptive.navigation3` library dependency to `core:ui` and relevant feature modules.
- Refactor `DesktopMainScreen` and `Main.kt` with minor formatting and indentation updates for better readability.
- Update `MainScreen` (Android) and `DesktopMainScreen` to manage their own `NavBackStack` initialization internally.
- Refactor `MainScreen` to obtain `UIViewModel` via Koin injection instead of receiving it as a parameter from `MainActivity`.
- Remove default bottom padding from `MeshtasticAppShell` and associated screen-level modifiers to allow for more flexible layout orchestration.
- Simplify `DesktopMainScreen` by moving backstack management inside the composable and cleaning up the navigation provider logic.
- Remove redundant lint suppressions in `Main.kt` following the simplification of the main screen composable structure.
- Clean up imports and normalize the usage of `MeshtasticNavDisplay` and `MeshtasticNavigationSuite` across platforms.
- Introduce `MeshtasticNavDisplay` in `core:ui` to encapsulate shared Navigation 3 configuration, including entry decorators, scene strategies, and transitions.
- Integrate `rememberViewModelStoreNavEntryDecorator` to provide entry-scoped `ViewModelStoreOwner` support, ensuring ViewModels are automatically cleared when their backstack entry is popped.
- Configure `DialogSceneStrategy` to enable navigation-driven dialogs that respect backstack lifecycle and predictive back gestures.
- Implement a standardized 350 ms crossfade transition for both forward and pop navigation across all platforms.
- Refactor `app` and `desktop` host modules to utilize `MeshtasticNavDisplay`, removing redundant manual configuration of `NavDisplay` and decorators.
- Update `core:ui` dependencies to include `lifecycle-viewmodel-navigation3` and move it away from platform-specific host modules.
- Update architectural documentation (`AGENTS.md`, `GEMINI.md`, and decision logs) to reflect the adoption of centralized navigation and ViewModel scoping patterns.
- Update Navigation 3 to `1.1.0-beta01`, JetBrains Lifecycle to `2.11.0-alpha02`, and Compose Multiplatform to `1.11.0-beta01`.
- Integrate `ViewModelStoreNavEntryDecorator` and `SaveableStateHolderNavEntryDecorator` into `NavDisplay` for both Android and Desktop shells.
- Enable automatic ViewModel scoping where ViewModels obtained via `koinViewModel()` inside `entry<T>` blocks are now tied to the backstack entry's lifetime and cleared on pop.
- Add `jetbrains.lifecycle.viewmodel.navigation3` dependency to support entry-level `ViewModelStore` management.
- Update `AGENTS.md`, `GEMINI.md`, and `copilot-instructions.md` to reflect the transition from Activity/Window-scoped ViewModels to entry-scoped lifecycles.
- Introduce `navigation3-api-alignment-2026-03.md` to document the audit of Navigation 3 Scene architecture and Material 3 Adaptive integration.
- Update `kmp-status.md` and existing decision docs to reflect the new dependency baseline and predictive back handling via `NavigationBackHandler`.
