feat: persist session ID across restarts

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.

src/api-client.ts

@@ -39,6 +39,11 @@ export class ApiClient {
     return this.currentSessionId;
   }
 
+  /** Restore a previously-saved session ID (from plugin data). */
+  setSessionId(id: string): void {
+    this.currentSessionId = id || null;
+  }
+
   /** The root URL without the /v1 suffix, e.g. http://192.168.1.12:8642 */
   private get rootUrl(): string {
     // baseUrl ends with /v1; strip it to reach the server root

src/chat-view.ts

@@ -16,10 +16,12 @@ export interface ApiClient {
   ): Promise<ChatCompletionResponse>;
 }
 
-/** Persistence interface — saves/loads chat messages via plugin data. */
+/** Persistence interface — saves/loads chat state via plugin data. */
 export interface ChatPersistence {
   loadMessages(): Message[];
   saveMessages(messages: Message[]): Promise<void>;
+  loadSessionId(): string;
+  saveSessionId(sessionId: string): Promise<void>;
 }
 
 export const VIEW_TYPE = "hermes-chat-view";
@@ -547,6 +549,7 @@ export class ChatView extends ItemView {
       if (response.sessionId) {
         this.chatState.sessionId = response.sessionId;
         this.updateStatus(response.model, response.sessionId);
+        this.persistence?.saveSessionId(response.sessionId);
       }
     } catch (error: any) {
       if (contentDiv) {

src/main.ts

@@ -25,11 +25,21 @@ export default class HermesChatPlugin extends Plugin {
             this.settings.chatMessages = messages;
             await this.saveData(this.settings);
           },
+          loadSessionId: () => this.settings.chatSessionId ?? "",
+          saveSessionId: async (id) => {
+            this.settings.chatSessionId = id;
+            await this.saveData(this.settings);
+          },
         };
         const view = new ChatView(leaf, client, this.contextBridge!, persistence);
         view.setContextActive(this.settings.enableContextInjection);
         view.setSlashCommands(this.getAllCommands());
         view.setChatFontSize(this.settings.chatFontSize);
+        // Restore previous session for conversation continuity
+        if (this.settings.chatSessionId) {
+          client.setSessionId(this.settings.chatSessionId);
+          view.updateStatus("hermes-agent", this.settings.chatSessionId);
+        }
         return view;
       }
     );

src/settings.ts

@@ -11,6 +11,7 @@ export interface HermesChatSettings {
   chatFontSize: number;
   customCommands: { trigger: string; description: string; prompt: string }[];
   chatMessages: Message[];
+  chatSessionId: string;
 }
 
 /** Built-in slash commands shipped with the plugin. */
@@ -40,6 +41,7 @@ export const DEFAULT_SETTINGS: HermesChatSettings = {
   chatFontSize: 14,
   customCommands: [],
   chatMessages: [],
+  chatSessionId: "",
 };
 
 export class HermesChatSettingTab extends PluginSettingTab {