feat(vllm-dev): pick qwen4_exp vision support to vllm-dev branch

src/registry/qwen3_vl.rs

@@ -137,7 +137,8 @@ impl ModelProcessorSpec for Qwen3VLVisionSpec {
         let is_qwen3_5 = id.contains("qwen3.5")
             || id.contains("qwen3.6")
             || model_type.is_some_and(|mt| mt == "qwen3_5" || mt == "qwen3_5_moe");
-        is_qwen3_vl || is_qwen3_5
+        let is_qwen4_exp = model_type.is_some_and(|mt| mt == "qwen4_exp");
+        is_qwen3_vl || is_qwen3_5 || is_qwen4_exp
     }
 
     fn placeholder_token(&self, metadata: &ModelMetadata) -> RegistryResult<String> {
@@ -503,4 +504,23 @@ mod tests {
             .expect("should match qwen3.5 alias");
         assert_eq!(spec.name(), "qwen3_vl");
     }
+
+    #[test]
+    fn qwen4_exp_matches_alias_via_model_type() {
+        let tokenizer = TestTokenizer::new(&[("<|image_pad|>", 151655)]);
+        let config = json!({
+            "model_type": "qwen4_exp",
+            "image_token_id": 151655,
+        });
+        let metadata = ModelMetadata {
+            model_id: "custom-model",
+            tokenizer: &tokenizer,
+            config: &config,
+        };
+        let registry = ModelRegistry::new();
+        let spec = registry
+            .lookup(&metadata)
+            .expect("should match qwen4_exp alias");
+        assert_eq!(spec.name(), "qwen3_vl");
+    }
 }

src/vision/processor.rs

@@ -203,6 +203,7 @@ impl VisionProcessorRegistry {
     /// - `qwen2.5-vl` -> Qwen2VLProcessor (same preprocessing as Qwen2-VL)
     /// - `qwen3-vl` -> Qwen3VLProcessor (patch_size=16, [0.5,0.5,0.5] normalization)
     /// - `qwen3.5` / `qwen3_5` -> Qwen3VLProcessor (Qwen3.5 reuses Qwen3-VL preprocessing)
+    /// - `qwen4_exp` / `qwen4-exp` -> Qwen3VLProcessor (same vision tower as Qwen3.5)
     /// - `phi-3-vision` -> Phi3VisionProcessor (HD transform with 336x336 tiles)
     pub fn with_defaults() -> Self {
         let mut registry = Self::new();
@@ -272,6 +273,16 @@ impl VisionProcessorRegistry {
             Box::new(super::processors::Qwen3VLProcessor::new()),
         );
 
+        // Qwen4-Exp: same vision tower as Qwen3.5
+        registry.register(
+            "qwen4_exp",
+            Box::new(super::processors::Qwen3VLProcessor::new()),
+        );
+        registry.register(
+            "qwen4-exp",
+            Box::new(super::processors::Qwen3VLProcessor::new()),
+        );
+
         // Register Qwen2-VL (matches Qwen/Qwen2-VL-*, etc.)
         registry.register(
             "qwen2-vl",
@@ -443,4 +454,14 @@ mod tests {
             .expect("phi3 processor by model_type");
         assert_eq!(processor.model_name(), "phi3-vision");
     }
+
+    #[test]
+    fn test_registry_find_qwen4_exp_model_type_fallback() {
+        let registry = VisionProcessorRegistry::with_defaults();
+
+        let processor = registry
+            .find("custom-model", Some("qwen4_exp"))
+            .expect("qwen3 processor by qwen4_exp model_type");
+        assert_eq!(processor.model_name(), "qwen3-vl");
+    }
 }