fix: Android null-safety Gson crash + AgentChat full UX overhaul (Round 1-4)
Android:
- Add NullSafeStringAdapter to GsonBuilder globally to prevent null String injection into non-nullable Kotlin fields
- Add defensive null-safe mappings in AgentRepository and all UI Text() calls
Frontend AgentChat (4 rounds):
- Round 1: Stop generation button, server-side session history sync, smart scroll
- Round 2: Full markdown rendering (marked), file/image upload with drag-drop, message edit/delete
- Round 3: TTS speech (browser SpeechSynthesis), voice input (SpeechRecognition), empty state guidance, model/temperature selector
- Round 4: Extract shared chat core — useMarkdown, useFileUpload, ChatMessageBubble, ChatInputArea modules — merge AgentChat.vue and AgentChatPreview.vue divergent code
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
renjianbo
fbf8dbbe86
