fix(kiro): AmazonQ endpoint origin CLI -> AI_EDITOR

With origin=CLI, q.us-east-1.amazonaws.com returns only 3 base models
(sonnet-4.5, sonnet-4, haiku-4.5) and rejects everything else with
INVALID_MODEL_ID. With origin=AI_EDITOR it returns the full catalog
(opus-4.5/4.6/4.7, sonnet-4.6, haiku-4.5, deepseek, minimax, glm, qwen,
auto).

Verified via direct curl to /ListAvailableModels on both origin values
with two different tokens.

proxy/kiro.go

@@ -35,7 +35,7 @@ var kiroEndpoints = []kiroEndpoint{
 	},
 	{
 		URL:       "https://q.us-east-1.amazonaws.com/generateAssistantResponse",
-		Origin:    "CLI",
+		Origin:    "AI_EDITOR",
 		AmzTarget: "AmazonQDeveloperStreamingService.SendMessage",
 		Name:      "AmazonQ",
 	},