- Change ChatMode enum values from numeric (0,1,2) to string literals ("read_only", "edit", "planning")
- Move chat mode state management from ChatWindow to SettingsService with persistence
- Add chat mode awareness to system prompts and tool validation
- Replace Map with WeakMap for settings subscribers to prevent memory leaks
- Add type-safe event handlers to EventService
- Update esbuild and TypeScript targets from ES2018/ES2020 to ES2022
- Add requiresEditModeEnabled() validation to prevent tool hallucination in read-only mode
- Update all test fixtures to include chatMode in mock settings
- Remove unused `path` property from Conversation class and its test
- Initialize `items` and `conversations` arrays in ConversationHistoryModal
- Use `Exception.messageFrom()` for safer error serialization in StreamingMarkdownService
- Fix redundant type cast in obsidian mock's Events.on()
- Bump @anthropic-ai/sdk, @google/genai, openai, esbuild, svelte, typescript, vitest, and other minor deps
