Add support for OpenAI's o1 models by making max_response_tokens optional

The other prerequisite seems to be not using a `prompt` (`prompt: null`),
but we already supported this.

It'd be nice to add an optional `max_completion_tokens` parameter as
well, for the benefit of the o1 models, but this is not yet supported by
async-openai.
Possibly tracked here: https://github.com/64bit/async-openai/issues/272

src/agent/provider/anthropic/controller.rs

@@ -129,7 +129,7 @@ impl ControllerTrait for Controller {
                 &text_generation_config.model_id,
                 &prompt_message,
                 conversation_messages,
-                text_generation_config.max_response_tokens,
+                Some(text_generation_config.max_response_tokens),
                 text_generation_config.max_context_tokens,
             );
 

src/agent/provider/groq/mod.rs

@@ -15,7 +15,7 @@ pub fn default_config() -> Config {
     if let Some(ref mut config) = config.text_generation.as_mut() {
         config.model_id = "llama3-70b-8192".to_owned();
         config.max_context_tokens = 131_072;
-        config.max_response_tokens = 4096;
+        config.max_response_tokens = Some(4096);
     }
 
     if let Some(ref mut config) = config.speech_to_text.as_mut() {

src/agent/provider/localai/mod.rs

@@ -13,7 +13,7 @@ pub fn default_config() -> Config {
     if let Some(ref mut config) = config.text_generation.as_mut() {
         config.model_id = "gpt-4".to_owned();
         config.max_context_tokens = 128_000;
-        config.max_response_tokens = 4096;
+        config.max_response_tokens = Some(4096);
     }
 
     if let Some(ref mut config) = config.text_to_speech.as_mut() {

src/agent/provider/ollama/mod.rs

@@ -17,7 +17,7 @@ pub fn default_config() -> Config {
     if let Some(ref mut config) = config.text_generation.as_mut() {
         config.model_id = "gemma2:2b".to_owned();
         config.max_context_tokens = 128_000;
-        config.max_response_tokens = 4096;
+        config.max_response_tokens = Some(4096);
     }
 
     config

src/agent/provider/openai/config.rs

@@ -56,7 +56,7 @@ pub struct TextGenerationConfig {
     pub temperature: f32,
 
     #[serde(default)]
-    pub max_response_tokens: u32,
+    pub max_response_tokens: Option<u32>,
 
     #[serde(default)]
     pub max_context_tokens: u32,
@@ -68,7 +68,7 @@ impl Default for TextGenerationConfig {
             model_id: default_text_model_id(),
             prompt: Some(default_prompt().to_owned()),
             temperature: super::super::default_temperature(),
-            max_response_tokens: 16_384,
+            max_response_tokens: Some(16_384),
             max_context_tokens: 128_000,
         }
     }

src/agent/provider/openai/controller.rs

@@ -131,12 +131,18 @@ impl ControllerTrait for Controller {
             .temperature_override
             .unwrap_or(text_generation_config.temperature);
 
-        let request = CreateChatCompletionRequestArgs::default()
-            .max_tokens(text_generation_config.max_response_tokens)
+        let mut request_builder = CreateChatCompletionRequestArgs::default();
+
+        request_builder
             .model(&text_generation_config.model_id)
             .temperature(temperature)
-            .messages(openai_conversation_messages)
-            .build()?;
+            .messages(openai_conversation_messages);
+
+        if let Some(max_response_tokens) = text_generation_config.max_response_tokens {
+            request_builder.max_tokens(max_response_tokens);
+        }
+
+        let request = request_builder.build()?;
 
         if let Ok(request_as_json) = serde_json::to_string(&request) {
             tracing::trace!(

src/agent/provider/openai_compat/config.rs

@@ -66,7 +66,7 @@ pub struct TextGenerationConfig {
     pub temperature: f32,
 
     #[serde(default)]
-    pub max_response_tokens: u32,
+    pub max_response_tokens: Option<u32>,
 
     #[serde(default)]
     pub max_context_tokens: u32,
@@ -78,7 +78,7 @@ impl Default for TextGenerationConfig {
             model_id: default_text_model_id(),
             prompt: Some(default_prompt().to_owned()),
             temperature: super::super::default_temperature(),
-            max_response_tokens: 4096,
+            max_response_tokens: Some(4096),
             max_context_tokens: 128_000,
         }
     }

src/agent/provider/openai_compat/controller.rs

@@ -131,12 +131,15 @@ impl ControllerTrait for Controller {
 
         let max_tokens = text_generation_config
             .max_response_tokens
-            .try_into()
-            .expect("Failed converting max_response_tokens from u32 to i32");
+            .map(|max_response_tokens| {
+                max_response_tokens
+                    .try_into()
+                    .expect("Failed converting max_response_tokens from u32 to i32")
+            });
 
         let request = ChatBody {
             model: text_generation_config.model_id.clone(),
-            max_tokens: Some(max_tokens),
+            max_tokens,
             temperature: Some(temperature),
             top_p: None,
             n: Some(1),

src/agent/provider/openai_compat/mod.rs

@@ -56,7 +56,7 @@ pub fn default_config() -> Config {
 
     if let Some(text_generation) = &mut config.text_generation {
         text_generation.model_id = "some-model".to_string();
-        text_generation.max_response_tokens = 4096;
+        text_generation.max_response_tokens = Some(4096);
         text_generation.max_context_tokens = 128_000;
     }
 

src/agent/provider/openrouter/mod.rs

@@ -14,7 +14,7 @@ pub fn default_config() -> Config {
     if let Some(ref mut config) = config.text_generation.as_mut() {
         config.model_id = "mattshumer/reflection-70b:free".to_owned();
         config.max_context_tokens = 8192;
-        config.max_response_tokens = 2048;
+        config.max_response_tokens = Some(2048);
     }
 
     config

src/agent/provider/togetherai/mod.rs

@@ -14,7 +14,7 @@ pub fn default_config() -> Config {
     if let Some(ref mut config) = config.text_generation.as_mut() {
         config.model_id = "meta-llama/Meta-Llama-3.1-405B-Instruct-Turbo".to_owned();
         config.max_context_tokens = 8192;
-        config.max_response_tokens = 2048;
+        config.max_response_tokens = Some(2048);
     }
 
     config