Update to latest Mistral AI API (v1.0.0)

- Replace closed Model enum with flexible string-based Model type
  with constructor methods for all current models (Mistral Large 3,
  Small 4, Magistral, Codestral, Devstral, Pixtral, Voxtral, etc.)
- Add new API endpoints: FIM completions, Files, Fine-tuning, Batch
  jobs, OCR, Audio transcription, Moderations/Classifications, and
  Agent completions (sync + async for all)
- Add new chat fields: frequency_penalty, presence_penalty, stop,
  n, parallel_tool_calls, reasoning_effort, min_tokens, json_schema
  response format
- Add embedding fields: output_dimension, output_dtype
- Tool parameters now accept raw JSON Schema (serde_json::Value)
  instead of limited enum types
- Add tool call IDs and Required tool choice variant
- Add DELETE HTTP method support and multipart file upload
- Bump thiserror to v2, add reqwest multipart feature
- Remove strum dependency (no longer needed)
- Update all tests and examples for new API

examples/chat_with_streaming.rs

@@ -1,6 +1,6 @@
 use futures::stream::StreamExt;
 use mistralai_client::v1::{
-    chat::{ChatMessage, ChatMessageRole, ChatParams},
+    chat::{ChatMessage, ChatParams},
     client::Client,
     constants::Model,
 };
@@ -11,14 +11,10 @@ async fn main() {
     // This example suppose you have set the `MISTRAL_API_KEY` environment variable.
     let client = Client::new(None, None, None, None).unwrap();
 
-    let model = Model::OpenMistral7b;
-    let messages = vec![ChatMessage {
-        role: ChatMessageRole::User,
-        content: "Tell me a short happy story.".to_string(),
-        tool_calls: None,
-    }];
+    let model = Model::mistral_small_latest();
+    let messages = vec![ChatMessage::new_user_message("Tell me a short happy story.")];
     let options = ChatParams {
-        temperature: 0.0,
+        temperature: Some(0.0),
         random_seed: Some(42),
         ..Default::default()
     };
@@ -31,9 +27,10 @@ async fn main() {
         .for_each(|chunk_result| async {
             match chunk_result {
                 Ok(chunks) => chunks.iter().for_each(|chunk| {
-                    print!("{}", chunk.choices[0].delta.content);
-                    io::stdout().flush().unwrap();
-                    // => "Once upon a time, [...]"
+                    if let Some(content) = &chunk.choices[0].delta.content {
+                        print!("{}", content);
+                        io::stdout().flush().unwrap();
+                    }
                 }),
                 Err(error) => {
                     eprintln!("Error processing chunk: {:?}", error)
@@ -41,5 +38,5 @@ async fn main() {
             }
         })
         .await;
-    print!("\n") // To persist the last chunk output.
+    println!();
 }