fix: reduce conversation history memory use

Load lightweight conversation summaries and hydrate full history only when
needed, preserving search, copy, export, queued requests, and remote questions.
Keep unchanged image reconciliation messages stable so list refreshes no
longer resend the entire saved history.

Prepare Desktop 0.13.6 with the approved bilingual notes and aligned feature
matrices. Agent remains 0.13.0; no LoongArch preview or navigation demo edits
are included. Development validation passed 4301 tests with 67 skipped;
the user requested CI validation instead of repeating local release checks.

Release note: 历史会话按需加载，减少切回应用时的重复保存和内存占用，同时保留完整历史、搜索与续聊。

resources/release-notes.json

@@ -1,6 +1,34 @@
 {
   "formatVersion": 1,
   "releases": [
+    {
+      "version": "0.13.6",
+      "releasedAt": "2026-09-15",
+      "notes": {
+        "zh-CN": {
+          "highlights": [],
+          "features": [],
+          "fixes": [
+            "**历史会话更省内存**：减少打开应用、刷新列表和切换会话时加载的历史数据，降低资源占用。历史详情按需读取，完整记录、全文搜索、复制、导出和续聊保持可用。",
+            "**避免重复保存历史消息**：修复切回应用或刷新会话时，未变化的消息仍被反复保存的问题。减少重复处理，同时保留图片状态更新、后台审批和远程待答问题。"
+          ],
+          "notices": [
+            "本次仅更新 Desktop，Agent 保持 **0.13.0**，无需因这两项修复重新更新 Host 环境。"
+          ]
+        },
+        "en-US": {
+          "highlights": [],
+          "features": [],
+          "fixes": [
+            "**Lower memory use with conversation history**: Reduced the history data loaded when opening the app, refreshing the list, and switching conversations. Details load on demand while complete records, full-text search, copy, export, and continued conversations remain available.",
+            "**Avoid repeatedly saving unchanged messages**: Fixed unchanged messages being saved again when returning to the app or refreshing conversations. This reduces repeated processing while preserving image updates, background approvals, and pending remote questions."
+          ],
+          "notices": [
+            "This release updates Desktop only. Agent remains at **0.13.0**, and these fixes do not require another Host environment update."
+          ]
+        }
+      }
+    },
     {
       "version": "0.13.5",
       "releasedAt": "2026-09-15",