Rescue work from claudomator-work: question/answer, ratelimit, start-next-task

Merges features developed in /site/doot.terst.org/claudomator-work (a
stale clone) into the canonical repo:

- executor: QuestionRegistry for human-in-the-loop answers, rate limit
  detection and exponential backoff retry (ratelimit.go, question.go)
- executor/claude.go: process group isolation (SIGKILL orphans on cancel),
  os.Pipe for reliable stdout drain, backoff retry on rate limits
- api/scripts.go: POST /api/scripts/start-next-task handler
- api/server.go: startNextTaskScript field, answer-question route,
  BroadcastQuestion for WebSocket question events
- web: Cancel/Restart buttons, question banner UI, log viewer, validate
  section, WebSocket auto-connect

All tests pass.

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

1 files changed, 50 insertions, 0 deletions

diff --git a/internal/api/scripts.go b/internal/api/scripts.go
new file mode 100644
index 0000000..492570b
--- /dev/null
+++ b/internal/api/scripts.go
@@ -0,0 +1,50 @@
+package api
+
+import (
+	"bytes"
+	"context"
+	"net/http"
+	"os/exec"
+	"path/filepath"
+	"time"
+)
+
+const scriptTimeout = 30 * time.Second
+
+func (s *Server) startNextTaskScriptPath() string {
+	if s.startNextTaskScript != "" {
+		return s.startNextTaskScript
+	}
+	return filepath.Join(s.workDir, "scripts", "start-next-task")
+}
+
+func (s *Server) handleStartNextTask(w http.ResponseWriter, r *http.Request) {
+	ctx, cancel := context.WithTimeout(r.Context(), scriptTimeout)
+	defer cancel()
+
+	scriptPath := s.startNextTaskScriptPath()
+	cmd := exec.CommandContext(ctx, scriptPath)
+
+	var stdout, stderr bytes.Buffer
+	cmd.Stdout = &stdout
+	cmd.Stderr = &stderr
+
+	err := cmd.Run()
+	exitCode := 0
+	if err != nil {
+		if exitErr, ok := err.(*exec.ExitError); ok {
+			exitCode = exitErr.ExitCode()
+		} else {
+			s.logger.Error("start-next-task: script execution failed", "error", err, "path", scriptPath)
+			writeJSON(w, http.StatusInternalServerError, map[string]string{
+				"error": "script execution failed: " + err.Error(),
+			})
+			return
+		}
+	}
+
+	writeJSON(w, http.StatusOK, map[string]interface{}{
+		"output":    stdout.String(),
+		"exit_code": exitCode,
+	})
+}