fix: Enhance Kol Variable Rendering and Management

- Updated the regex for placeholder matching to support more flexible key formats.
- Refactored variable storage to allow both ID and key lookups in rendering.
- Improved schema validation to check for duplicate keys and enforce non-empty keys.
- Added new utility functions for variable value lookup and display name generation.
- Enhanced tests to cover new key-based variable scenarios.
- Refactored KolPrompt repository to simplify prompt storage and management, including the removal of obsolete revision handling.
- Introduced new API endpoints for saving, activating, and archiving prompts.
- Added new utility functions for handling Kol placeholders and platform options in the admin web.
- Implemented database migrations to simplify prompt storage structure and ensure data integrity.

server/internal/scheduler/schedule_dispatch_worker.go

@@ -103,10 +103,10 @@ func (w *ScheduleDispatchWorker) run(ctx context.Context) {
 }
 
 func (w *ScheduleDispatchWorker) runOnce(parent context.Context) {
-	ctx, cancel := context.WithTimeout(parent, w.timeout)
-	defer cancel()
-
-	if count, err := w.hydrateMissingNextRuns(ctx); err != nil {
+	ctx, cancel := w.stageContext(parent)
+	count, err := w.hydrateMissingNextRuns(ctx)
+	cancel()
+	if err != nil {
 		if w.logger != nil {
 			w.logger.Warn("schedule dispatch hydrate missing next_run_at failed", zap.Error(err))
 		}
@@ -114,7 +114,10 @@ func (w *ScheduleDispatchWorker) runOnce(parent context.Context) {
 		w.logger.Info("schedule dispatch hydrated next_run_at", zap.Int("task_count", count))
 	}
 
-	if paused, stats, err := w.shouldPauseDispatch(ctx); err != nil {
+	ctx, cancel = w.stageContext(parent)
+	paused, stats, err := w.shouldPauseDispatch(ctx)
+	cancel()
+	if err != nil {
 		if w.logger != nil {
 			w.logger.Warn("schedule dispatch inspect generation queue failed", zap.Error(err))
 		}
@@ -129,7 +132,9 @@ func (w *ScheduleDispatchWorker) runOnce(parent context.Context) {
 		return
 	}
 
+	ctx, cancel = w.stageContext(parent)
 	tasks, err := w.claimDueSchedules(ctx)
+	cancel()
 	if err != nil {
 		if w.logger != nil {
 			w.logger.Warn("schedule dispatch claim due schedules failed", zap.Error(err))
@@ -477,6 +482,13 @@ func schedulerDispatchConcurrency(cfg config.SchedulerConfig) int {
 	return 1
 }
 
+func (w *ScheduleDispatchWorker) stageContext(parent context.Context) (context.Context, context.CancelFunc) {
+	if parent == nil {
+		parent = context.Background()
+	}
+	return context.WithTimeout(parent, w.timeout)
+}
+
 func (w *ScheduleDispatchWorker) invalidateScheduleTaskCaches(updates []scheduleTaskCacheUpdate) {
 	if w == nil || w.cache == nil || len(updates) == 0 {
 		return