feat: resume support, summary extraction, and task state improvements

- Extend Resume to CANCELLED, FAILED, and BUDGET_EXCEEDED tasks
- Add summary extraction from agent stdout stream-json output
- Fix storage: persist stdout/stderr/artifact_dir paths in UpdateExecution
- Clear question_json on ResetTaskForRetry
- Resume BLOCKED tasks in preserved sandbox so Claude finds its session
- Add planning preamble: CLAUDOMATOR_SUMMARY_FILE env var + summary step
- Update ADR-002 with new state transitions
- UI style improvements

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

1 files changed, 57 insertions, 0 deletions

diff --git a/internal/executor/summary.go b/internal/executor/summary.go
new file mode 100644
index 0000000..a942de0
--- /dev/null
+++ b/internal/executor/summary.go
@@ -0,0 +1,57 @@
+package executor
+
+import (
+	"bufio"
+	"encoding/json"
+	"os"
+	"strings"
+)
+
+// extractSummary reads a stream-json stdout log and returns the text following
+// the last "## Summary" heading found in any assistant text block.
+// Returns empty string if the file cannot be read or no summary is found.
+func extractSummary(stdoutPath string) string {
+	f, err := os.Open(stdoutPath)
+	if err != nil {
+		return ""
+	}
+	defer f.Close()
+
+	var last string
+	scanner := bufio.NewScanner(f)
+	scanner.Buffer(make([]byte, 1024*1024), 1024*1024)
+	for scanner.Scan() {
+		if text := summaryFromLine(scanner.Bytes()); text != "" {
+			last = text
+		}
+	}
+	return last
+}
+
+// summaryFromLine parses a single stream-json line and returns the text after
+// "## Summary" if the line is an assistant text block containing that heading.
+func summaryFromLine(line []byte) string {
+	var event struct {
+		Type    string `json:"type"`
+		Message struct {
+			Content []struct {
+				Type string `json:"type"`
+				Text string `json:"text"`
+			} `json:"content"`
+		} `json:"message"`
+	}
+	if err := json.Unmarshal(line, &event); err != nil || event.Type != "assistant" {
+		return ""
+	}
+	for _, block := range event.Message.Content {
+		if block.Type != "text" {
+			continue
+		}
+		idx := strings.Index(block.Text, "## Summary")
+		if idx == -1 {
+			continue
+		}
+		return strings.TrimSpace(block.Text[idx+len("## Summary"):])
+	}
+	return ""
+}