fix(review): capture Claude reviewer model via transcript backfill (#1373)

Claude review subprocesses run via `claude -p` don't reliably report a model
through lifecycle hooks (the ModelUpdate path is flaky in headless mode), so
per-session checkpoint metadata landed with "model": "" for Claude reviewer
sessions, while codex/pi reviewers record theirs. Root cause: ClaudeCodeAgent
did not implement agent.ModelExtractor, so condense's sessionStateBackfillModel
fallback (AsModelExtractor -> ExtractModel) was a no-op for Claude; the model
relied solely on the flaky hook path.

Implement ExtractModel on ClaudeCodeAgent: parse the transcript and return the
last non-empty model from an assistant line (mirrors pi/copilotcli/factoryai).
Condense already calls this when state.ModelName == "", so review (and any
hook-missed) Claude sessions now record a non-empty model deterministically.

Verified against real recorded data: a real agent_review row in
entire/checkpoints/v1 with model="" (skills=[/review]) — running the new
ExtractModel on that session's stored transcript recovers "claude-opus-4-7",
which is exactly the value the condense backfill writes. Surfaces in
entire.io's per-reviewer attribution (entirehq/entire.io#2271).

Note: the transcript carries the base model id ("claude-opus-4-7"), not the
hook's context-window variant ("claude-opus-4-7[1m]"), so backfilled models
omit the [1m] suffix — a correct, non-empty id, slightly less precise.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Entire-Checkpoint: 41d9aa9acef6

Author: peyton-alt

cmd/entire/cli/agent/claudecode/transcript.go

@@ -88,6 +88,35 @@ func ExtractModifiedFiles(lines []TranscriptLine) []string {
 	return files
 }
 
+// ExtractModel returns the LLM model recorded in the transcript, satisfying
+// agent.ModelExtractor. Claude review subprocesses spawned via `claude -p` do
+// not reliably report the model through lifecycle hooks (the ModelUpdate path
+// is flaky in headless mode), so condense backfills it from the transcript
+// here — the same mechanism codex/pi/etc. rely on. Returns the last non-empty
+// model seen on an assistant line, or "" when the transcript carries none.
+func (c *ClaudeCodeAgent) ExtractModel(transcriptData []byte) (string, error) {
+	lines, err := transcript.ParseFromBytes(transcriptData)
+	if err != nil {
+		return "", fmt.Errorf("parse transcript: %w", err)
+	}
+	model := ""
+	for _, line := range lines {
+		if line.Type != envelopeTypeAssistant {
+			continue
+		}
+		var msg struct {
+			Model string `json:"model"`
+		}
+		if err := json.Unmarshal(line.Message, &msg); err != nil {
+			continue
+		}
+		if msg.Model != "" {
+			model = msg.Model
+		}
+	}
+	return model, nil
+}
+
 // TruncateAtUUID returns transcript lines up to and including the line with given UUID
 func TruncateAtUUID(lines []TranscriptLine, uuid string) []TranscriptLine {
 	if uuid == "" {

cmd/entire/cli/agent/claudecode/transcript_test.go

@@ -869,3 +869,45 @@ func TestExtractAllModifiedFiles_SubagentOnlyChanges(t *testing.T) {
 		t.Errorf("missing expected file %q", f)
 	}
 }
+
+func TestExtractModel(t *testing.T) {
+	t.Parallel()
+	data := []byte(`{"type":"assistant","uuid":"a1","message":{"model":"claude-opus-4-7[1m]","content":[{"type":"text","text":"hi"}]}}` + "\n")
+	model, err := (&ClaudeCodeAgent{}).ExtractModel(data)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if model != "claude-opus-4-7[1m]" {
+		t.Errorf("model = %q, want claude-opus-4-7[1m]", model)
+	}
+}
+
+func TestExtractModel_MostRecentWins(t *testing.T) {
+	t.Parallel()
+	data := []byte(strings.Join([]string{
+		`{"type":"assistant","uuid":"a1","message":{"model":"claude-sonnet-4-6","content":[]}}`,
+		`{"type":"assistant","uuid":"a2","message":{"model":"claude-opus-4-8","content":[]}}`,
+		"",
+	}, "\n"))
+	model, err := (&ClaudeCodeAgent{}).ExtractModel(data)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if model != "claude-opus-4-8" {
+		t.Errorf("model = %q, want claude-opus-4-8 (most recent)", model)
+	}
+}
+
+func TestExtractModel_EmptyWhenAbsent(t *testing.T) {
+	t.Parallel()
+	// A review subprocess transcript with no model field on any assistant line
+	// yields "" (caller treats that as "no model available").
+	data := []byte(`{"type":"assistant","uuid":"a1","message":{"content":[{"type":"text","text":"hi"}]}}` + "\n")
+	model, err := (&ClaudeCodeAgent{}).ExtractModel(data)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if model != "" {
+		t.Errorf("model = %q, want empty", model)
+	}
+}