Fixed: #936

feat(cliproxy): support multiple aliases for OAuth model mappings

- Updated mapping logic to allow multiple aliases per upstream model name.
- Adjusted `SanitizeOAuthModelMappings` to ensure aliases remain unique within channels.
- Added test cases to validate multi-alias scenarios.
- Updated example config to clarify multi-alias support.

sdk/cliproxy/service_oauth_model_mappings_test.go

@@ -56,3 +56,37 @@ func TestApplyOAuthModelMappings_ForkAddsAlias(t *testing.T) {
 		t.Fatalf("expected forked model name %q, got %q", "models/g5", out[1].Name)
 	}
 }
+
+func TestApplyOAuthModelMappings_ForkAddsMultipleAliases(t *testing.T) {
+	cfg := &config.Config{
+		OAuthModelMappings: map[string][]config.ModelNameMapping{
+			"codex": {
+				{Name: "gpt-5", Alias: "g5", Fork: true},
+				{Name: "gpt-5", Alias: "g5-2", Fork: true},
+			},
+		},
+	}
+	models := []*ModelInfo{
+		{ID: "gpt-5", Name: "models/gpt-5"},
+	}
+
+	out := applyOAuthModelMappings(cfg, "codex", "oauth", models)
+	if len(out) != 3 {
+		t.Fatalf("expected 3 models, got %d", len(out))
+	}
+	if out[0].ID != "gpt-5" {
+		t.Fatalf("expected first model id %q, got %q", "gpt-5", out[0].ID)
+	}
+	if out[1].ID != "g5" {
+		t.Fatalf("expected second model id %q, got %q", "g5", out[1].ID)
+	}
+	if out[1].Name != "models/g5" {
+		t.Fatalf("expected forked model name %q, got %q", "models/g5", out[1].Name)
+	}
+	if out[2].ID != "g5-2" {
+		t.Fatalf("expected third model id %q, got %q", "g5-2", out[2].ID)
+	}
+	if out[2].Name != "models/g5-2" {
+		t.Fatalf("expected forked model name %q, got %q", "models/g5-2", out[2].Name)
+	}
+}