feat(runtime): add process watch patterns, unified backup/import, pluggable context engine, token usage, and codex device login

pkg/agent/loop_usage_test.go

@@ -0,0 +1,26 @@
+package agent
+
+import (
+	"testing"
+
+	"github.com/YspCoder/clawgo/pkg/providers"
+)
+
+func TestMergeUsageTotals(t *testing.T) {
+	t.Parallel()
+
+	var result llmTurnLoopResult
+	mergeUsageTotals(&result, &providers.UsageInfo{PromptTokens: 10, CompletionTokens: 4, TotalTokens: 0})
+	mergeUsageTotals(&result, &providers.UsageInfo{PromptTokens: 3, CompletionTokens: 2, TotalTokens: 9})
+
+	if result.promptTokens != 13 {
+		t.Fatalf("prompt tokens = %d, want 13", result.promptTokens)
+	}
+	if result.completionTokens != 6 {
+		t.Fatalf("completion tokens = %d, want 6", result.completionTokens)
+	}
+	// First merge falls back to prompt+completion (14), second uses explicit total (9).
+	if result.totalTokens != 23 {
+		t.Fatalf("total tokens = %d, want 23", result.totalTokens)
+	}
+}