feat: support VertexAI provider (#153)

* support: vertexai

fix

fix

set default for vertexai

added comment

fix

fix

* create schema

* fix README.md

* fix order

* added pupularity

* set tools if tools is exists

restore commentout

* fix comment

* set summarizer model

internal/llm/models/models.go

@@ -43,6 +43,7 @@ var ProviderPopularity = map[ModelProvider]int{
 	ProviderOpenRouter: 5,
 	ProviderBedrock:    6,
 	ProviderAzure:      7,
+	ProviderVertexAI:   8,
 }
 
 var SupportedModels = map[ModelID]Model{
@@ -95,4 +96,5 @@ func init() {
 	maps.Copy(SupportedModels, AzureModels)
 	maps.Copy(SupportedModels, OpenRouterModels)
 	maps.Copy(SupportedModels, XAIModels)
+	maps.Copy(SupportedModels, VertexAIGeminiModels)
 }