refactor(Solid): use schema-aligned docs from model layer, remove doc rebuild in SolidStorage

Model layer builds full message/conversation docs; Solid only persists and
merges existing Pod data for partial updates.

Author: PreciousOritsedere

api/models/Conversation.js

@@ -138,7 +138,17 @@ module.exports = {
 
     if (isSolidUser(req)) {
       try {
-        const savedConvo = await saveConvoToSolid(req, baseConvo, metadata);
+        // Full document aligned with schema (same shape as MongoDB); SolidStorage adds messages + timestamps
+        const finalConversationId = newConversationId || conversationId;
+        const convoDocument = {
+          ...baseConvo,
+          conversationId: finalConversationId,
+          user: req.user.id,
+        };
+        if (newConversationId && newConversationId !== conversationId) {
+          convoDocument.previousConversationId = conversationId;
+        }
+        const savedConvo = await saveConvoToSolid(req, convoDocument, metadata);
         return savedConvo;
       } catch (error) {
         logger.error('[saveConvo] Error saving conversation to Solid Pod', error);

api/models/Message.js

@@ -82,7 +82,14 @@ async function saveMessage(req, params, metadata) {
 
   if (isSolidUser(req)) {
     try {
-      const savedMessage = await saveMessageToSolid(req, baseMessage, metadata);
+      // Full document aligned with schema (same shape as MongoDB); SolidStorage only persists it
+      const messageDocument = {
+        ...baseMessage,
+        user: req.user.id,
+        createdAt: baseMessage.createdAt || new Date().toISOString(),
+        updatedAt: new Date().toISOString(),
+      };
+      const savedMessage = await saveMessageToSolid(req, messageDocument, metadata);
       return savedMessage;
     } catch (err) {
       logger.error('Error saving message to Solid Pod:', err);