fix(#686): implement robust history pagination (#687)

* fix(#686): implement robust history pagination

Honor server-returned offset, degrade gracefully on older servers, and parse JSON tool results.

* fix(ci): repair unit-test compilation and pagination test mocks

- Remove trailing blank line in SessionMessagesResponse.kt (ktlint)
- Replace unresolved io.mockk.eq/coAnswers usage in ChatViewModelTest with
  an ordered-call counter inside coAnswers, which compiles and runs on
  MockK 1.14.11 (eq is a matcher-scope member, not a top-level import)
- Align HermesApiServiceMockWebServerTest with the PR's JsonElement content
  model (contentText) and the new include_compacted=true default query param

All unit tests pass locally with the ByteBuddy agent preload.

---------

Co-authored-by: M57 <hy4ri@users.noreply.github.com>

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

@@ -247,11 +247,11 @@ class HermesApiServiceMockWebServerTest {
             assertEquals(3, messages.size)
 
             assertEquals("user", messages[0].role)
-            assertEquals("Hello Hermes", messages[0].content)
+            assertEquals("Hello Hermes", messages[0].contentText)
             assertEquals("1718000000", messages[0].timestampText)
 
             assertEquals("assistant", messages[1].role)
-            assertEquals("Hi! How can I help?", messages[1].content)
+            assertEquals("Hi! How can I help?", messages[1].contentText)
 
             assertEquals("tool", messages[2].role)
             assertEquals("tool_execution", messages[2].type)
@@ -270,11 +270,68 @@ class HermesApiServiceMockWebServerTest {
 
             assertTrue(response.isSuccessful)
             assertEquals(
-                "/api/sessions/desktop/session/messages?limit=150&offset=300",
+                "/api/sessions/desktop/session/messages?limit=150&offset=300&include_compacted=true",
                 mockServer.takeRequest().path,
             )
         }
 
+    @Test
+    fun getSessionMessages_withJsonObjectToolResult_deserializesSuccessfully() =
+        runBlocking {
+            mockServer.enqueue(
+                MockResponse()
+                    .setResponseCode(200)
+                    .setBody(
+                        """
+                        {
+                            "messages": [
+                                {
+                                    "role": "tool",
+                                    "content": {"status": "ok", "items": [1, 2]},
+                                    "type": "tool_result"
+                                }
+                            ]
+                        }
+                        """.trimIndent(),
+                    ),
+            )
+
+            val response = api.getSessionMessages("test-session-id")
+            assertTrue(response.isSuccessful)
+
+            val body = response.body()
+            assertNotNull(body)
+            assertEquals(1, body!!.messages.size)
+            assertEquals("tool", body.messages[0].role)
+            assertEquals("{\"status\":\"ok\",\"items\":[1,2]}", body.messages[0].contentText)
+        }
+
+    @Test
+    fun getSessionMessages_withOffsetAndTotal_deserializesPaginationFields() =
+        runBlocking {
+            mockServer.enqueue(
+                MockResponse()
+                    .setResponseCode(200)
+                    .setBody(
+                        """
+                        {
+                            "messages": [],
+                            "offset": 45,
+                            "total": 120
+                        }
+                        """.trimIndent(),
+                    ),
+            )
+
+            val response = api.getSessionMessages("test-session-id")
+            assertTrue(response.isSuccessful)
+
+            val body = response.body()
+            assertNotNull(body)
+            assertEquals(45, body!!.offset)
+            assertEquals(120, body.total)
+        }
+
     @Test
     fun getSessionMessages_withNullRole_doesNotCrash() =
         runBlocking {
@@ -303,7 +360,7 @@ class HermesApiServiceMockWebServerTest {
             assertNotNull(body)
             assertEquals(1, body!!.messages.size)
             assertNull(body.messages[0].role)
-            assertEquals("Plain content", body.messages[0].content)
+            assertEquals("Plain content", body.messages[0].contentText)
             assertNull(body.messages[0].timestamp)
         }
 
@@ -383,7 +440,7 @@ class HermesApiServiceMockWebServerTest {
             val request = mockServer.takeRequest()
             assertEquals(
                 "path should contain the session ID with slashes preserved",
-                "/api/sessions/session/with/slashes/messages?offset=0",
+                "/api/sessions/session/with/slashes/messages?offset=0&include_compacted=true",
                 request.path,
             )
         }