feat(session): extend Attempt with tier, timing, and verdict fields

internal/session/session.go

@@ -32,9 +32,14 @@ type Entry struct {
 type Attempt struct {
 	Attempt       int    `json:"attempt"`
 	Model         string `json:"model"`
+	Tier          string `json:"tier"`                    // local | subagent | managed
+	DurationMs    int64  `json:"duration_ms"`
+	WarmStart     bool   `json:"warm_start"`              // model already loaded in llama-swap
+	Verified      bool   `json:"verified"`
+	Verdict       string `json:"verdict,omitempty"`       // accept | escalate | error
+	Feedback      string `json:"feedback,omitempty"`      // verifier feedback on escalation
 	OutputSummary string `json:"output_summary,omitempty"`
 	RunnerOutput  string `json:"runner_output,omitempty"`
-	Verified      bool   `json:"verified"`
 }
 
 // Append writes entry as a single JSON line to sessionsDir/{sessionID}.jsonl.