webui: Agentic Loop + MCP Client with support for Tools, Resources and Prompts (#18655)

tools/server/webui/docs/flows/database-flow.md

@@ -66,6 +66,14 @@ sequenceDiagram
     DbSvc-->>Store: rootMessageId
     deactivate DbSvc
 
+    Store->>DbSvc: createSystemMessage(convId, content, parentId)
+    activate DbSvc
+    DbSvc->>DbSvc: Create message {role: "system", parent: parentId}
+    DbSvc->>Dexie: db.messages.add(systemMsg)
+    Dexie->>IDB: INSERT
+    DbSvc-->>Store: DatabaseMessage
+    deactivate DbSvc
+
     Store->>DbSvc: createMessageBranch(message, parentId)
     activate DbSvc
     DbSvc->>DbSvc: Generate UUID for new message
@@ -116,6 +124,13 @@ sequenceDiagram
     end
     DbSvc->>Dexie: db.messages.delete(msgId)
     Dexie->>IDB: DELETE target message
+
+    alt target message has a parent
+        DbSvc->>Dexie: db.messages.get(parentId)
+        DbSvc->>DbSvc: parent.children.filter(id !== msgId)
+        DbSvc->>Dexie: db.messages.update(parentId, {children})
+        Note right of DbSvc: Remove deleted message from parent's children[]
+    end
     deactivate DbSvc
 
     %% ═══════════════════════════════════════════════════════════════════════════
@@ -125,12 +140,16 @@ sequenceDiagram
     Store->>DbSvc: importConversations(data)
     activate DbSvc
     loop each conversation in data
-        DbSvc->>DbSvc: Generate new UUIDs (avoid conflicts)
-        DbSvc->>Dexie: db.conversations.add(conversation)
-        Dexie->>IDB: INSERT conversation
-        loop each message
-            DbSvc->>Dexie: db.messages.add(message)
-            Dexie->>IDB: INSERT message
+        DbSvc->>Dexie: db.conversations.get(conv.id)
+        alt conversation already exists
+            Note right of DbSvc: Skip duplicate (keep existing)
+        else conversation is new
+            DbSvc->>Dexie: db.conversations.add(conversation)
+            Dexie->>IDB: INSERT conversation
+            loop each message
+                DbSvc->>Dexie: db.messages.add(message)
+                Dexie->>IDB: INSERT message
+            end
         end
     end
     deactivate DbSvc