When the Hermes Gateway returns X-Hermes-Session-Id, it is now
saved to settings.chatSessionId via the ChatPersistence interface.
On restart, the factory restores the session ID into the ApiClient
so subsequent requests continue the same conversation.
Changes:
- Added chatSessionId to HermesChatSettings + DEFAULT_SETTINGS
- Extended ChatPersistence with loadSessionId/saveSessionId
- Added ApiClient.setSessionId() for restoring saved IDs
- ChatView.handleSend() persists sessionId when received
- main.ts factory restores session ID and updates status bar
Fixes the 'Marco!/Bolo!' test — conversation continuity now
survives Obsidian restarts.