Move all business logic and state (~35 variables, ~15 functions) from
the 1540-line ChatScreen @Composable into ChatScreenViewModel.
ChatScreen is now a thin rendering layer (~430 lines) that reads VM
state and wires UI events to VM methods. Android-framework-only concerns
(ActivityResultLaunchers, DrawerState, LazyListState, keyboard insets)
stay in the Composable.
Changes:
- New ChatScreenViewModel.kt: messages, streaming, conversation mgmt,
sidebar actions, file upload, voice recording, TTS, live call, unlock
- ChatScreen.kt: pure UI, delegates all logic to vm.*
- Haptics.kt: add createHaptics(Context) factory for non-Composable use
- SessionViewModel: store nullable for test construction
- MainActivity: instantiates ChatScreenViewModel
Tests: 12 new unit tests for ChatScreenViewModel (state transitions,
newChat reset, mode toggles, edit/delete, password dialog lifecycle).
All 90 tests pass.
40db869717