test: fix Anthropic unit tests to match corrected message ordering

Update test expectations to match the fixed message ordering where
context messages come first (chronological order), then the main
prompt. This aligns with the fix that resolved context conversation
issues in the Anthropic API integration.

The corrected order ensures proper conversation flow:
1. Previous context (user question)
2. Previous context (assistant answer)
3. Current user prompt

All 111 Anthropic unit test assertions now pass.

Author: lucaromagnoli

tests/unit/test_anthropic_types.cpp

@@ -201,15 +201,15 @@ TEST_CASE("Anthropic MessagesRequest structure", "[anthropic][unit]") {
         REQUIRE(anthropicRequest.temperature == 0.5f);
         REQUIRE(anthropicRequest.messages.size() == 3);  // 2 context + 1 current
 
-        // Check the main prompt message
+        // Check context messages come first (chronological order)
         REQUIRE(anthropicRequest.messages[0].role == Anthropic::MessageRole::USER);
-        REQUIRE(anthropicRequest.messages[0].content[0].text == "Current question");
+        REQUIRE(anthropicRequest.messages[0].content[0].text == "Previous question");
+        REQUIRE(anthropicRequest.messages[1].role == Anthropic::MessageRole::ASSISTANT);
+        REQUIRE(anthropicRequest.messages[1].content[0].text == "Previous answer");
 
-        // Check context messages
-        REQUIRE(anthropicRequest.messages[1].role == Anthropic::MessageRole::USER);
-        REQUIRE(anthropicRequest.messages[1].content[0].text == "Previous question");
-        REQUIRE(anthropicRequest.messages[2].role == Anthropic::MessageRole::ASSISTANT);
-        REQUIRE(anthropicRequest.messages[2].content[0].text == "Previous answer");
+        // Check the main prompt message comes last
+        REQUIRE(anthropicRequest.messages[2].role == Anthropic::MessageRole::USER);
+        REQUIRE(anthropicRequest.messages[2].content[0].text == "Current question");
     }
 
     SECTION("LLMRequest conversion with invalid context") {
@@ -223,9 +223,10 @@ TEST_CASE("Anthropic MessagesRequest structure", "[anthropic][unit]") {
         LLMRequest llmRequest(config, "Main prompt", context);
         auto anthropicRequest = Anthropic::MessagesRequest::fromLLMRequest(llmRequest);
 
-        // Should have main prompt + 1 valid context message
+        // Should have 1 valid context message + main prompt
         REQUIRE(anthropicRequest.messages.size() == 2);
-        REQUIRE(anthropicRequest.messages[1].content[0].text == "Should be included");
+        REQUIRE(anthropicRequest.messages[0].content[0].text == "Should be included");
+        REQUIRE(anthropicRequest.messages[1].content[0].text == "Main prompt");
     }
 }