fix: remove nextRun recalculation from getAgents() that blocked cron

The getAgents() function was recalculating nextRun to future dates when
it found past values. This prevented the cron scheduler from ever
finding due agents (nextRun <= now was always false since getAgents
had already pushed it to the future).

Also fix toast polling: use null sentinel for agents without initial
actions so first execution is still detected. Limit cron to 3 agents
per cycle and add logging.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

memento-note/app/actions/agent-actions.ts

@@ -206,26 +206,6 @@ export async function getAgents() {
       orderBy: { createdAt: 'desc' }
     })
 
-    // Fix stale nextRun: recalculate if in the past for scheduled agents
-    const now = new Date()
-    for (const agent of agents) {
-      if (agent.frequency !== 'manual' && agent.nextRun && new Date(agent.nextRun) < now) {
-        const nextRun = calculateNextRun({
-          frequency: agent.frequency,
-          scheduledTime: agent.scheduledTime,
-          scheduledDay: agent.scheduledDay,
-          timezone: agent.timezone,
-        })
-        if (nextRun) {
-          await prisma.agent.update({
-            where: { id: agent.id },
-            data: { nextRun },
-          })
-          agent.nextRun = nextRun
-        }
-      }
-    }
-
     return agents
   } catch (error) {
     console.error('Error fetching agents:', error)