fix: preserve runtime configuration references

Projects, channels, conversations, and Agent Runtimes now retain dynamic default references while explicit model selections remain pinned. Compatible fallback resolution stays aligned across settings validation, runtime creation, labels, context metrics, DeepSeek Harness browser routing, and remote project saves.

Prepare the bilingual Desktop 0.12.11 release metadata and keep Agent 0.11.22 as the published remote baseline.

Release note: 修复默认模型与 Runtime 配置变化后项目、通道和对话选择失去跟随关系的问题；显式选择仍保持固定，新请求使用当前兼容配置。

FEATURES.md

@@ -21,7 +21,7 @@ otherwise.
   packages target compatible x64 and arm64 environments, including UOS, Kylin,
   Hygon, Zhaoxin, Kunpeng, and Phytium systems. This is not vendor certification.
   LoongArch has a separate experimental loong64 preview outside standard
-  releases and automatic updates; no preview is planned for 0.12.10. See the
+  releases and automatic updates; no preview is planned for 0.12.11. See the
   [preview boundaries](./docs/development/loongarch-preview-build.md).
 - [x] **Configurable global shortcut**: Enable, disable, or record an Electron
   accelerator under Platform Features / General. The default remains
@@ -187,7 +187,7 @@ otherwise.
   failure, Agent `SIGKILL`/restart, and recovery from a reopened Desktop SQLite
   database. Successful tool START/END events appear exactly once, with no
   Prompt, provider, or tool replay observed. The current Agent source lock is
-  `0.11.22`, while the current Desktop release candidate is `0.12.10`; formal
+  `0.11.22`, while the current Desktop release candidate is `0.12.11`; formal
   publication status follows the separate Agent and Desktop
   release channels. Current macOS source has passed native package installation,
   detached lifecycle, Attach, real Ask/Execute, and cancellation of tools in