Feat: add sync_dsl parameter to support synchronizing modifications to existing sessions (#5843)

When accessing the /api/v1/agents/{agent_id}/completions API, sessions
created before agent modifications retain the old DSL data. To use the
latest agent configuration (like new prompts) in historical sessions, I
added the sync_dsl parameter. It defaults to False to maintain existing
behavior and only synchronizes when set to True. If needed, a manual
synchronization API can be created to trigger the sync explicitly.

docs/references/http_api_reference.md

@@ -2513,6 +2513,7 @@ Asks a specified agent a question to start an AI-powered conversation.
   - `"stream"`: `boolean`
   - `"session_id"`: `string`
   - `"user_id"`: `string`(optional)
+  - `"sync_dsl"`: `boolean` (optional)
   - other parameters: `string`
 ##### Request example
 If the **Begin** component does not take parameters, the following code will create a session.
@@ -2565,6 +2566,8 @@ curl --request POST \
   The ID of the session. If it is not provided, a new session will be generated.
 - `"user_id"`: (*Body parameter*), `string`  
   The optional user-defined ID. Valid *only* when no `session_id` is provided.
+- `"sync_dsl"`: (*Body parameter*), `boolean`
+  Whether to synchronize the changes to existing sessions when an agent is modified, defaults to `false`.
 - Other parameters: (*Body Parameter*)  
   Parameters specified in the **Begin** component.