Advanced paste: Tweak Foundry Local Displayed Model and start server if server is turned on when using AP (#43529)

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fix/what does it change/how was it tested (even manually, if necessary)?
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## Summary of the Pull Request
1. Foundry local model name should not prefixed by fl://
2. If foundry service is shutdown, we should not just fail it, we should
start it then call FL to make availability better.

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## PR Checklist

- [ ] Closes: #xxx
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## Detailed Description of the Pull Request / Additional comments

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## Validation Steps Performed
Verified locally:
1. Manually disable foundry local service, then run AP with foundry
local, it can return result instead of direct failure.
2. 
<img width="659" height="294" alt="image"
src="https://github.com/user-attachments/assets/113da451-7131-4ce7-ae82-0ccf772ad8aa"
/>
<img width="988" height="192" alt="image"
src="https://github.com/user-attachments/assets/aa3650ba-668a-40c4-ad8a-303e09000dd4"
/>
![Uploading image.png…]()

src/modules/AdvancedPaste/AdvancedPaste/Services/CustomActions/FoundryLocalPasteProvider.cs

@@ -23,7 +23,7 @@ public sealed class FoundryLocalPasteProvider : IPasteAIProvider
 
     public static PasteAIProviderRegistration Registration { get; } = new(SupportedTypes, config => new FoundryLocalPasteProvider(config));
 
-    private static readonly LanguageModelService LanguageModels = LanguageModelService.CreateDefault();
+    private static readonly FoundryLocalModelProvider _modelProvider = FoundryLocalModelProvider.Instance;
 
     private readonly PasteAIConfig _config;
 
@@ -72,11 +72,11 @@ public sealed class FoundryLocalPasteProvider : IPasteAIProvider
                 throw new PasteActionException(
                     "No Foundry Local model selected",
                     new InvalidOperationException("Model identifier is required"),
-                    aiServiceMessage: "Please select a model in the AI provider settings. Model identifier should be in the format 'fl://model-name'.");
+                    aiServiceMessage: "Please select a model in the AI provider settings.");
             }
 
             cancellationToken.ThrowIfCancellationRequested();
-            var chatClient = LanguageModels.GetClient(modelReference);
+            var chatClient = _modelProvider.GetIChatClient(modelReference);
             if (chatClient is null)
             {
                 throw new PasteActionException(
@@ -85,9 +85,6 @@ public sealed class FoundryLocalPasteProvider : IPasteAIProvider
                     aiServiceMessage: "The model may not be downloaded or the Foundry Local service may not be running. Please check the model status in settings.");
             }
 
-            // Extract actual model ID from the URL (format: fl://modelId)
-            var actualModelId = modelReference.Replace("fl://", string.Empty).Trim('/');
-
             var userMessageContent = $"""
                 User instructions:
                 {prompt}
@@ -104,7 +101,7 @@ public sealed class FoundryLocalPasteProvider : IPasteAIProvider
                 new(ChatRole.User, userMessageContent),
             };
 
-            var chatOptions = CreateChatOptions(_config?.SystemPrompt, actualModelId);
+            var chatOptions = CreateChatOptions(_config?.SystemPrompt, modelReference);
 
             progress?.Report(0.1);