Gemini 3 Flash (#1590)

* Gemini 3 Flash

Upgrade gemini-cli to the latest version and update the flash preset to the latest flash model.

* fmt

crates/executors/default_profiles.json

@@ -37,7 +37,7 @@
       },
       "FLASH": {
         "GEMINI": {
-          "model": "gemini-2.5-flash",
+          "model": "gemini-3-flash-preview",
           "yolo": true
         }
       },

crates/executors/src/executors/gemini.rs

@@ -36,8 +36,7 @@ pub struct Gemini {
 
 impl Gemini {
     fn build_command_builder(&self) -> CommandBuilder {
-        let mut builder =
-            CommandBuilder::new("npx -y @google/gemini-cli@0.21.0-nightly.20251204.3da4fd5f7");
+        let mut builder = CommandBuilder::new("npx -y @google/gemini-cli@0.21.1");
 
         if let Some(model) = &self.model {
             builder = builder.extend_params(["--model", model.as_str()]);