test: add integration tests for Classify, BatchGenerate, Info, Metrics

Verified on RX 7800 XT (gfx1100, ROCm 7.2):
- Classify: greedy single-token via max_tokens=1
- BatchGenerate: sequential multi-prompt generation
- Info: GGUF metadata (gemma3, 26 layers, Q5_K_M)
- Metrics: 250 tok/s decode, 3244 MiB VRAM

Co-Authored-By: Virgil <virgil@lethean.io>

rocm_integration_test.go

@@ -201,6 +201,100 @@ func TestROCm_ConcurrentRequests(t *testing.T) {
 	}
 }
 
+func TestROCm_Classify(t *testing.T) {
+	skipIfNoROCm(t)
+	skipIfNoModel(t)
+
+	b := &rocmBackend{}
+	m, err := b.LoadModel(testModel, inference.WithContextLen(2048))
+	require.NoError(t, err)
+	defer m.Close()
+
+	ctx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
+	defer cancel()
+
+	prompts := []string{
+		"The capital of France is",
+		"2 + 2 =",
+	}
+
+	results, err := m.Classify(ctx, prompts)
+	require.NoError(t, err)
+	require.Len(t, results, 2)
+
+	for i, r := range results {
+		assert.NotEmpty(t, r.Token.Text, "classify result %d should have a token", i)
+		t.Logf("Classify %d: %q", i, r.Token.Text)
+	}
+}
+
+func TestROCm_BatchGenerate(t *testing.T) {
+	skipIfNoROCm(t)
+	skipIfNoModel(t)
+
+	b := &rocmBackend{}
+	m, err := b.LoadModel(testModel, inference.WithContextLen(2048))
+	require.NoError(t, err)
+	defer m.Close()
+
+	ctx, cancel := context.WithTimeout(context.Background(), 60*time.Second)
+	defer cancel()
+
+	prompts := []string{
+		"The capital of France is",
+		"The capital of Germany is",
+	}
+
+	results, err := m.BatchGenerate(ctx, prompts, inference.WithMaxTokens(8))
+	require.NoError(t, err)
+	require.Len(t, results, 2)
+
+	for i, r := range results {
+		require.NoError(t, r.Err, "batch result %d error", i)
+		assert.NotEmpty(t, r.Tokens, "batch result %d should have tokens", i)
+
+		var sb strings.Builder
+		for _, tok := range r.Tokens {
+			sb.WriteString(tok.Text)
+		}
+		t.Logf("Batch %d: %s", i, sb.String())
+	}
+}
+
+func TestROCm_InfoAndMetrics(t *testing.T) {
+	skipIfNoROCm(t)
+	skipIfNoModel(t)
+
+	b := &rocmBackend{}
+	m, err := b.LoadModel(testModel, inference.WithContextLen(2048))
+	require.NoError(t, err)
+	defer m.Close()
+
+	// Info should be populated from GGUF metadata.
+	info := m.Info()
+	assert.Equal(t, "gemma3", info.Architecture)
+	assert.Greater(t, info.NumLayers, 0, "expected non-zero layer count")
+	assert.Greater(t, info.QuantBits, 0, "expected non-zero quant bits")
+	t.Logf("Info: arch=%s layers=%d quant=%d-bit group=%d",
+		info.Architecture, info.NumLayers, info.QuantBits, info.QuantGroup)
+
+	// Generate some tokens to populate metrics.
+	ctx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
+	defer cancel()
+
+	for range m.Generate(ctx, "Hello", inference.WithMaxTokens(4)) {
+	}
+	require.NoError(t, m.Err())
+
+	met := m.Metrics()
+	assert.Greater(t, met.GeneratedTokens, 0, "expected generated tokens")
+	assert.Greater(t, met.TotalDuration, time.Duration(0), "expected non-zero duration")
+	assert.Greater(t, met.DecodeTokensPerSec, float64(0), "expected non-zero decode throughput")
+	t.Logf("Metrics: gen=%d tok, total=%s, decode=%.1f tok/s, vram=%d MiB",
+		met.GeneratedTokens, met.TotalDuration, met.DecodeTokensPerSec,
+		met.ActiveMemoryBytes/(1024*1024))
+}
+
 func TestROCm_DiscoverModels(t *testing.T) {
 	dir := filepath.Dir(testModel)
 	if _, err := os.Stat(dir); err != nil {