feat: paginate, sync, and display branched sessions (#563)

* mobile: 以 Desktop Sessions 作为聊天历史源

* mobile: 修复快速连接崩溃与无标题会话隐藏

* mobile: 对齐 Desktop 标题并恢复完整历史

* mobile: 分离 Desktop 存储 ID 与运行 Session ID

* mobile: 将新对话持久化为 Desktop Session

* mobile: 渲染 Desktop 本地媒体

* feat: 分页加载并同步当前会话

* fix: 显示分支会话名称与层级

* fix: align PR with upstream app contract

* fix: preserve upstream session RPC lifecycle

app/src/test/java/com/m57/hermescontrol/data/remote/HermesApiServiceMockWebServerTest.kt

@@ -141,7 +141,8 @@ class HermesApiServiceMockWebServerTest {
                                     "created_at": "2026-06-20T14:30:00Z",
                                     "message_count": 7,
                                     "status": "idle",
-                                    "source": "web"
+                                    "source": "web",
+                                    "parent_session_id": "abc-123"
                                 }
                             ],
                             "total": 2,
@@ -173,6 +174,7 @@ class HermesApiServiceMockWebServerTest {
             assertEquals(7, second.message_count)
             assertEquals("idle", second.status)
             assertEquals("web", second.source)
+            assertEquals("abc-123", second.parent_session_id)
         }
 
     @Test
@@ -254,6 +256,24 @@ class HermesApiServiceMockWebServerTest {
             assertEquals("tool_execution", messages[2].type)
         }
 
+    @Test
+    fun getSessionMessages_sendsPaginationQuery() =
+        runBlocking {
+            mockServer.enqueue(
+                MockResponse()
+                    .setResponseCode(200)
+                    .setBody("{\"messages\": []}"),
+            )
+
+            val response = api.getSessionMessages("desktop/session", limit = 150, offset = 300)
+
+            assertTrue(response.isSuccessful)
+            assertEquals(
+                "/api/sessions/desktop/session/messages?limit=150&offset=300",
+                mockServer.takeRequest().path,
+            )
+        }
+
     @Test
     fun getSessionMessages_withNullRole_doesNotCrash() =
         runBlocking {