Clean multimodal tool results before storage (#911)

packages/server/src/db/hermes/session-store.ts

@@ -4,6 +4,7 @@
  */
 import { isSqliteAvailable, getDb } from '../index'
 import { SESSIONS_TABLE, MESSAGES_TABLE } from './schemas'
+import { normalizeMessageContentForStorageRole } from './message-content'
 
 // Re-export types for compatibility with sessions-db.ts consumers
 export interface HermesSessionRow {
@@ -377,7 +378,7 @@ export function addMessage(msg: {
     `INSERT INTO ${MESSAGES_TABLE} (session_id, role, content, tool_call_id, tool_calls, tool_name, timestamp, token_count, finish_reason, reasoning, reasoning_details, reasoning_content)
      VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)`,
   ).run(
-    msg.session_id, msg.role, msg.content,
+    msg.session_id, msg.role, normalizeMessageContentForStorageRole(msg.role, msg.content),
     msg.tool_call_id ?? null, toolCallsJson, msg.tool_name ?? null,
     msg.timestamp ?? Math.floor(Date.now() / 1000),
     msg.token_count ?? null, msg.finish_reason ?? null,
@@ -412,7 +413,7 @@ export function addMessages(msgs: Array<{
     for (const msg of msgs) {
       const toolCallsJson = msg.tool_calls ? JSON.stringify(msg.tool_calls) : null
       insert.run(
-        msg.session_id, msg.role, msg.content,
+        msg.session_id, msg.role, normalizeMessageContentForStorageRole(msg.role, msg.content),
         msg.tool_call_id ?? null, toolCallsJson, msg.tool_name ?? null,
         msg.timestamp ?? Math.floor(Date.now() / 1000),
         msg.token_count ?? null, msg.finish_reason ?? null,