Use Double instead of Float for portable ChatOptions

This change updates the type of portable chat options from Float to
Double. Affected options include:
- frequencyPenalty
- presencePenalty
- temperature
- topP

The motivation for this change is to simplify coding. In Java, Float
values require an "f" suffix (e.g., 0.5f), while Double values don't
need any suffix. This makes Double easier to type and reduces
potential errors from forgetting the "f" suffix.

APIs, tests, and documentation have been updated to reflect this
change.

Fixes gh-712

Signed-off-by: Thomas Vitale <ThomasVitale@users.noreply.github.com>

spring-ai-core/src/test/java/org/springframework/ai/chat/ChatBuilderTests.java

@@ -40,8 +40,8 @@ public class ChatBuilderTests {
 
 	@Test
 	void createNewChatOptionsTest() {
-		Float temperature = 1.1f;
-		Float topP = 2.2f;
+		Double temperature = 1.1;
+		Double topP = 2.2;
 		Integer topK = 111;
 
 		ChatOptions options = ChatOptionsBuilder.builder()
@@ -57,8 +57,8 @@ public class ChatBuilderTests {
 
 	@Test
 	void duplicateChatOptionsTest() {
-		Float initTemperature = 1.1f;
-		Float initTopP = 2.2f;
+		Double initTemperature = 1.1;
+		Double initTopP = 2.2;
 		Integer initTopK = 111;
 
 		ChatOptions options = ChatOptionsBuilder.builder()
@@ -71,8 +71,8 @@ public class ChatBuilderTests {
 
 	@Test
 	void createFunctionCallingOptionTest() {
-		Float temperature = 1.1f;
-		Float topP = 2.2f;
+		Double temperature = 1.1;
+		Double topP = 2.2;
 		Integer topK = 111;
 		List<FunctionCallback> functionCallbacks = new ArrayList<>();
 		Set<String> functions = new HashSet<>();

spring-ai-core/src/test/java/org/springframework/ai/chat/observation/DefaultChatModelObservationConventionTests.java

@@ -98,13 +98,13 @@ class DefaultChatModelObservationConventionTests {
 			.provider("superprovider")
 			.requestOptions(ChatOptionsBuilder.builder()
 				.withModel("mistral")
-				.withFrequencyPenalty(0.8f)
+				.withFrequencyPenalty(0.8)
 				.withMaxTokens(200)
-				.withPresencePenalty(1.0f)
+				.withPresencePenalty(1.0)
 				.withStopSequences(List.of("addio", "bye"))
-				.withTemperature(0.5f)
+				.withTemperature(0.5)
 				.withTopK(1)
-				.withTopP(0.9f)
+				.withTopP(0.9)
 				.build())
 			.build();
 		observationContext.setResponse(new ChatResponse(

spring-ai-core/src/test/java/org/springframework/ai/prompt/PromptTemplateTest.java

@@ -44,7 +44,7 @@ public class PromptTemplateTest {
 	public void testCreateWithEmptyModelAndChatOptions() {
 		String template = "This is a test prompt with no variables";
 		PromptTemplate promptTemplate = new PromptTemplate(template);
-		ChatOptions chatOptions = ChatOptionsBuilder.builder().withTemperature(0.7f).withTopK(3).build();
+		ChatOptions chatOptions = ChatOptionsBuilder.builder().withTemperature(0.7).withTopK(3).build();
 
 		Prompt prompt = promptTemplate.create(chatOptions);
 
@@ -60,7 +60,7 @@ public class PromptTemplateTest {
 		model.put("name", "Alice");
 		model.put("age", 30);
 		PromptTemplate promptTemplate = new PromptTemplate(template, model);
-		ChatOptions chatOptions = ChatOptionsBuilder.builder().withTemperature(0.5f).withMaxTokens(100).build();
+		ChatOptions chatOptions = ChatOptionsBuilder.builder().withTemperature(0.5).withMaxTokens(100).build();
 
 		Prompt prompt = promptTemplate.create(model, chatOptions);
 
@@ -79,7 +79,7 @@ public class PromptTemplateTest {
 
 		Map<String, Object> overriddenModel = new HashMap<>();
 		overriddenModel.put("color", "red");
-		ChatOptions chatOptions = ChatOptionsBuilder.builder().withTemperature(0.8f).build();
+		ChatOptions chatOptions = ChatOptionsBuilder.builder().withTemperature(0.8).build();
 
 		Prompt prompt = promptTemplate.create(overriddenModel, chatOptions);