feat(auth): add support for kiro OAuth model alias

- Introduced `kiro` channel and alias resolution in `oauth_model_alias` logic.
- Updated supported channels documentation and examples to include `kiro` and `github-copilot`.
- Enhanced unit tests to validate `kiro` alias functionality.

sdk/cliproxy/auth/oauth_model_alias_test.go

@@ -43,6 +43,15 @@ func TestResolveOAuthUpstreamModel_SuffixPreservation(t *testing.T) {
 			input:   "gemini-2.5-pro",
 			want:    "gemini-2.5-pro-exp-03-25",
 		},
+		{
+			name: "kiro alias resolves",
+			aliases: map[string][]internalconfig.OAuthModelAlias{
+				"kiro": {{Name: "kiro-claude-sonnet-4-5", Alias: "sonnet"}},
+			},
+			channel: "kiro",
+			input:   "sonnet",
+			want:    "kiro-claude-sonnet-4-5",
+		},
 		{
 			name: "config suffix takes priority",
 			aliases: map[string][]internalconfig.OAuthModelAlias{
@@ -152,6 +161,8 @@ func createAuthForChannel(channel string) *Auth {
 		return &Auth{Provider: "qwen"}
 	case "iflow":
 		return &Auth{Provider: "iflow"}
+	case "kiro":
+		return &Auth{Provider: "kiro"}
 	default:
 		return &Auth{Provider: channel}
 	}