feat(loop): agent loop（8 轮 + checkpoint + 流式 + 记忆注入/提取 + trace + 工具超时回喂）

internal/runtime/loop/step.go

@@ -0,0 +1,64 @@
+package loop
+
+import (
+	"context"
+	"fmt"
+
+	"git.yeij.top/AskaEth/Cyrene_v2/internal/runtime/agent"
+	"git.yeij.top/AskaEth/Cyrene_v2/internal/runtime/model"
+	"git.yeij.top/AskaEth/Cyrene_v2/internal/runtime/trace"
+)
+
+// stepOutcome is the loop's internal view of one model step, normalized from the
+// agent's *agent.StepResult (non-streaming) or the equivalent built by the
+// streaming path.
+type stepOutcome struct {
+	final      bool
+	text       string
+	toolCalls  []agent.ToolCall
+	stopReason string
+}
+
+// step runs a single model call. When an OnStream callback is configured it
+// drives the adapter's ChatStream directly, threading deltas to OnStream and
+// applying the loop's guardrails; otherwise it delegates to the agent's RunStep,
+// which runs the agent's own guardrails and records its own CallRecord. The whole
+// call is wrapped in an llm_call span so the M9 panel sees each LLM invocation.
+func (l *Loop) step(ctx context.Context, sessionID string, messages []model.Message) (*stepOutcome, error) {
+	_, llmSpan := l.span(ctx, "llm.call", trace.SpanKindLLM)
+
+	var (
+		out *stepOutcome
+		err error
+	)
+	if l.onStream != nil {
+		out, err = l.streamStep(ctx, messages)
+	} else {
+		out, err = l.agentStep(ctx, sessionID, messages)
+	}
+	if err != nil {
+		l.spanProp(llmSpan, "error", err.Error())
+		l.finishSpan(llmSpan, trace.SpanStatusError)
+		return nil, fmt.Errorf("loop: model step: %w", err)
+	}
+
+	l.spanProp(llmSpan, "stop_reason", out.stopReason)
+	l.spanProp(llmSpan, "tool_calls", len(out.toolCalls))
+	l.finishSpan(llmSpan, trace.SpanStatusOK)
+	return out, nil
+}
+
+// agentStep delegates a non-streaming step to the agent, which runs input and
+// output guardrails, calls the model and decodes any tool calls.
+func (l *Loop) agentStep(ctx context.Context, sessionID string, messages []model.Message) (*stepOutcome, error) {
+	sr, err := l.agent.RunStep(ctx, sessionID, messages)
+	if err != nil {
+		return nil, fmt.Errorf("loop: agent step: %w", err)
+	}
+	return &stepOutcome{
+		final:      sr.Final,
+		text:       sr.Text,
+		toolCalls:  sr.ToolCalls,
+		stopReason: sr.StopReason,
+	}, nil
+}