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, 5 insertions, 3 deletions

diff --git a/internal/executor/executor.go b/internal/executor/executor.go
index d25d3b4..51f468e 100644
--- a/internal/executor/executor.go
+++ b/internal/executor/executor.go
@@ -24,9 +24,10 @@ type Pool struct {
 	store         *storage.DB
 	logger        *slog.Logger
 
-	mu       sync.Mutex
-	active   int
-	resultCh chan *Result
+	mu        sync.Mutex
+	active    int
+	resultCh  chan *Result
+	Questions *QuestionRegistry
 }
 
 // Result is emitted when a task execution completes.
@@ -46,6 +47,7 @@ func NewPool(maxConcurrent int, runner Runner, store *storage.DB, logger *slog.L
 		store:         store,
 		logger:        logger,
 		resultCh:      make(chan *Result, maxConcurrent*2),
+		Questions:     NewQuestionRegistry(),
 	}
 }