fix(client): support vLLM "reasoning" field for thinking blocks

vLLM sends thinking content in a "reasoning" delta field, unlike
DeepSeek which uses "reasoning_content". Check both field names so
thinking blocks render for vLLM-hosted models like qwen3.6-27b-thinking.

Also update client tests to exercise thinking output and skip by default
so they don't run in Drone CI (require live LLM API).

backend/internal/client/client_test.go

@@ -10,9 +10,11 @@ import (
 	"reichard.io/aethera/internal/store"
 )
 
-const model = "devstral-small-2-instruct"
+const model = "vllm-qwen3.6-27b-thinking"
 
 func TestSendMessage(t *testing.T) {
+	t.Skip("requires live LLM API - run manually with: go test -run TestSendMessage ./internal/client/")
+
 	// Initialize Client
 	baseURL, err := url.Parse("https://llm-api.va.reichard.io/v1")
 	if err != nil {
@@ -21,17 +23,21 @@ func TestSendMessage(t *testing.T) {
 	client := NewClient(baseURL)
 
 	// Create Context
-	ctx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
+	ctx, cancel := context.WithTimeout(context.Background(), 120*time.Second)
 	defer cancel()
 
 	// Generate Text Stream
-	var buf bytes.Buffer
+	var contentBuf, thinkingBuf bytes.Buffer
 	_, err = client.SendMessage(ctx, []*store.Message{{
 		Role:    "user",
-		Content: "Hello, how are you?",
+		Content: "What is 2+2? Think step by step.",
 	}}, model, func(mc *MessageChunk) error {
+		if mc.Thinking != nil {
+			_, err := thinkingBuf.Write([]byte(*mc.Thinking))
+			return err
+		}
 		if mc.Message != nil {
-			_, err := buf.Write([]byte(*mc.Message))
+			_, err := contentBuf.Write([]byte(*mc.Message))
 			return err
 		}
 		return nil
@@ -40,17 +46,26 @@ func TestSendMessage(t *testing.T) {
 		t.Fatalf("Failed to generate text stream: %v", err)
 	}
 
-	// Verify Results
-	output := buf.String()
+	// Verify Thinking
+	thinking := thinkingBuf.String()
+	if thinking == "" {
+		t.Error("No thinking content was received")
+	} else {
+		t.Logf("Thinking (%d bytes): %s", len(thinking), thinking)
+	}
+
+	// Verify Content
+	output := contentBuf.String()
 	if output == "" {
 		t.Error("No content was written to the buffer")
 	} else {
-		t.Logf("Successfully received %d bytes from the stream", len(output))
-		t.Logf("Output: %s", output)
+		t.Logf("Content (%d bytes): %s", len(output), output)
 	}
 }
 
 func TestSummarizeChat(t *testing.T) {
+	t.Skip("requires live LLM API - run manually with: go test -run TestSummarizeChat ./internal/client/")
+
 	// Initialize Client
 	baseURL, err := url.Parse("https://llm-api.va.reichard.io/v1")
 	if err != nil {