fix(#219): add pagination to sessions history tab (#357)

* fix(#219): add pagination to sessions history tab

The /api/sessions endpoint was called without pagination params, so the server returned only its default limit of 20 sessions.

- SessionListResponse: added total/limit/offset fields from server response
- HermesApiService: added @Query params (limit, offset, order) to getSessions()
- SessionsViewModel: added loadMore() that appends pages, hasMore derived from total
- SessionsScreen: added 'Load more sessions' button + loading spinner at bottom of list

* chore: remove plan file from git

* fix: compilation errors in sessions pagination

* chore: gitignore plan files

* fix: remove duplicate brace

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

app/src/test/java/com/m57/hermescontrol/ui/chat/ChatViewModelTest.kt

@@ -292,7 +292,7 @@ class ChatViewModelTest {
             mockEventsFlow.emit(WsEvent.RpcResult(createReqId, mapOf("session_id" to "session-123")))
             advanceUntilIdle()
 
-            coEvery { ApiClient.hermesApi.getSessions() } returns
+            coEvery { ApiClient.hermesApi.getSessions(any(), any(), any()) } returns
                 mockk(relaxed = true) {
                     every { isSuccessful } returns true
                     every { body() } returns null
@@ -301,7 +301,7 @@ class ChatViewModelTest {
             viewModel.sendMessage("/sessions")
             advanceUntilIdle()
 
-            coVerify { ApiClient.hermesApi.getSessions() }
+            coVerify { ApiClient.hermesApi.getSessions(any(), any(), any()) }
         }
 
     @Test