fix(gemini): resolve compilation errors and final parameter alignment

src/models/mod.rs

@@ -12,8 +12,20 @@ pub struct ChatCompletionRequest {
     #[serde(default)]
     pub temperature: Option<f64>,
     #[serde(default)]
+    pub top_p: Option<f64>,
+    #[serde(default)]
+    pub top_k: Option<u32>,
+    #[serde(default)]
+    pub n: Option<u32>,
+    #[serde(default)]
+    pub stop: Option<Value>, // Can be string or array of strings
+    #[serde(default)]
     pub max_tokens: Option<u32>,
     #[serde(default)]
+    pub presence_penalty: Option<f64>,
+    #[serde(default)]
+    pub frequency_penalty: Option<f64>,
+    #[serde(default)]
     pub stream: Option<bool>,
     #[serde(default, skip_serializing_if = "Option::is_none")]
     pub tools: Option<Vec<Tool>>,
@@ -194,7 +206,13 @@ pub struct UnifiedRequest {
     pub model: String,
     pub messages: Vec<UnifiedMessage>,
     pub temperature: Option<f64>,
+    pub top_p: Option<f64>,
+    pub top_k: Option<u32>,
+    pub n: Option<u32>,
+    pub stop: Option<Vec<String>>,
     pub max_tokens: Option<u32>,
+    pub presence_penalty: Option<f64>,
+    pub frequency_penalty: Option<f64>,
     pub stream: bool,
     pub has_images: bool,
     pub tools: Option<Vec<Tool>>,
@@ -326,12 +344,28 @@ impl TryFrom<ChatCompletionRequest> for UnifiedRequest {
             })
             .collect();
 
+        let stop = match req.stop {
+            Some(Value::String(s)) => Some(vec![s]),
+            Some(Value::Array(a)) => Some(
+                a.into_iter()
+                    .filter_map(|v| v.as_str().map(|s| s.to_string()))
+                    .collect(),
+            ),
+            _ => None,
+        };
+
         Ok(UnifiedRequest {
             client_id: String::new(), // Will be populated by auth middleware
             model: req.model,
             messages,
             temperature: req.temperature,
+            top_p: req.top_p,
+            top_k: req.top_k,
+            n: req.n,
+            stop,
             max_tokens: req.max_tokens,
+            presence_penalty: req.presence_penalty,
+            frequency_penalty: req.frequency_penalty,
             stream: req.stream.unwrap_or(false),
             has_images,
             tools: req.tools,