feat(android): add search to task list screen

[dkhalife]

Summary

Adds search functionality to the Android task list screen.

Behavior

• Search icon (🔍) in the top-right of the app bar; tapping it animates the bar into a search field that takes focus automatically
• Full-width text field replaces the collapsing title bar during search; an ✕ icon replaces the search icon and cancels search + clears the query
• Substring match (case-insensitive) on task title; groups with no matching tasks are hidden automatically
• Navigation persistence: search state lives in the ViewModel so navigating to task details and pressing back restores the filtered view
• Cold-start reset: state is not persisted to disk — reopening the app shows no active search

Cursor-jump bug prevention

Previous patterns drove TextField from a ViewModel String, which recreated TextFieldValue without cursor info on every keystroke. This implementation keeps TextFieldValue (including cursor/selection) as local remember(isSearchActive) state. Only .text is pushed to the ViewModel. A LaunchedEffect(searchQuery) re-syncs the local value only when textFieldValue.text != searchQuery (navigation restoration), never during normal typing.

Files changed

File	Change
TaskListViewModel.kt	Add _searchQuery / _isSearchActive StateFlows + setters; inject into combine for reactive filtering
TaskListScreen.kt	Search UI: animated top bar swap, BasicTextField, focus management, search-aware empty state
AppNavigation.kt	Collect and wire search state/handlers to TaskListScreen
strings.xml	Add search hint, no-results strings, icon content descriptions

[Copilot]

Pull request overview

Adds an in-memory (non-persisted) search experience to the Android task list screen, with ViewModel-backed query/state for navigation restoration and reactive filtering of grouped tasks.

Changes:

• Introduces searchQuery / isSearchActive StateFlows in TaskListViewModel and applies case-insensitive substring filtering before grouping.
• Adds an animated top app bar swap on TaskListScreen to show a focused search field and a search-aware empty/no-results state.
• Wires search state + handlers through AppNavigation and adds the required string resources.

Show a summary per file

File	Description
android/app/src/main/res/values/strings.xml	Adds search hint, no-results messaging, and icon content descriptions.
android/app/src/main/java/com/dkhalife/tasks/viewmodel/TaskListViewModel.kt	Adds search StateFlows + setters and filters tasks in the grouping combine pipeline.
android/app/src/main/java/com/dkhalife/tasks/ui/screen/TaskListScreen.kt	Implements animated search UI in the top app bar, focus management, and search-aware empty state.
android/app/src/main/java/com/dkhalife/tasks/ui/navigation/AppNavigation.kt	Collects and passes search state/handlers between ViewModel and TaskListScreen.

Copilot's findings

• Files reviewed: 4/4 changed files
• Comments generated: 1