models: add support for gemma4-12b (#16457)

server/gemma4_test.go

@@ -50,6 +50,15 @@ func TestResolveGemma4Renderer(t *testing.T) {
 			},
 			want: gemma4RendererLarge,
 		},
+		{
+			name: "legacy 12b tag resolves large",
+			model: &Model{
+				Name:      "gemma-4-12b-it",
+				ShortName: "gemma-4-12b-it",
+				Config:    testConfigWithRenderer(gemma4RendererLegacy),
+			},
+			want: gemma4RendererLarge,
+		},
 		{
 			name: "legacy model type resolves small",
 			model: &Model{
@@ -64,6 +73,13 @@ func TestResolveGemma4Renderer(t *testing.T) {
 			},
 			want: gemma4RendererLarge,
 		},
+		{
+			name: "legacy 12b model type resolves large",
+			model: &Model{
+				Config: testConfigWithRendererAndType(gemma4RendererLegacy, "12B"),
+			},
+			want: gemma4RendererLarge,
+		},
 		{
 			name: "legacy unknown defaults small",
 			model: &Model{

server/renderer_resolution.go

@@ -12,10 +12,10 @@ const (
 	gemma4RendererSmall  = "gemma4-small"
 	gemma4RendererLarge  = "gemma4-large"
 
-	// Gemma 4 small templates cover the e2b/e4b family, while 26b/31b use the
-	// large template. Default to the small prompt unless the model is clearly in
-	// the large range.
-	gemma4LargeMinParameterCount = 16_000_000_000
+	// Gemma 4 small templates cover the e2b/e4b family, while 12b/26b/31b use
+	// the large template. Default to the small prompt unless the model is
+	// clearly in the large range.
+	gemma4LargeMinParameterCount = 12_000_000_000
 )
 
 func resolveRendererName(m *Model) string {
@@ -67,7 +67,7 @@ func gemma4RendererFromName(name string) (string, bool) {
 	switch {
 	case strings.Contains(lower, "e2b"), strings.Contains(lower, "e4b"):
 		return gemma4RendererSmall, true
-	case strings.Contains(lower, "26b"), strings.Contains(lower, "31b"):
+	case strings.Contains(lower, "12b"), strings.Contains(lower, "26b"), strings.Contains(lower, "31b"):
 		return gemma4RendererLarge, true
 	default:
 		return "", false