Add worker environment variables to Dokku setup guide

- Add TASK_REMINDER_HOUR, TASK_REMINDER_MINUTE, OVERDUE_REMINDER_HOUR, DAILY_DIGEST_HOUR config
- Document schedule times in UTC with explanation table
- Add worker verification steps to check logs

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

docs/DOKKU_SETUP.md

@@ -342,18 +342,26 @@ dokku letsencrypt:cron-job --add
 
 ## Set Up Worker Process
 
-The worker process handles background jobs (task reminders, email sending, etc.).
+The worker process handles background jobs (task reminders, overdue alerts, daily digests, email sending, etc.).
 
-### 1. Create Procfile (if not exists)
-
-The Dockerfile already handles this, but if you need a Procfile:
+### 1. Configure Worker Environment Variables
 
 ```bash
-# In your local repo, create Procfile:
-echo "web: /app/api" > Procfile
-echo "worker: /app/worker" >> Procfile
+dokku config:set casera-api \
+  TASK_REMINDER_HOUR=20 \
+  TASK_REMINDER_MINUTE=0 \
+  OVERDUE_REMINDER_HOUR=9 \
+  DAILY_DIGEST_HOUR=11
 ```
 
+**Schedule times are in UTC:**
+| Variable | Default | Description |
+|----------|---------|-------------|
+| `TASK_REMINDER_HOUR` | 20 | Hour to send "task due soon" notifications (8 PM UTC) |
+| `TASK_REMINDER_MINUTE` | 0 | Minute for task reminder |
+| `OVERDUE_REMINDER_HOUR` | 9 | Hour to send overdue task alerts (9 AM UTC) |
+| `DAILY_DIGEST_HOUR` | 11 | Hour to send daily summary (11 AM UTC) |
+
 ### 2. Scale Worker Process
 
 ```bash
@@ -364,6 +372,19 @@ dokku ps:scale casera-api worker=1
 dokku ps:report casera-api
 ```
 
+### 3. Verify Worker is Running
+
+```bash
+# Check worker logs
+dokku logs casera-api -p worker
+
+# Should see:
+# "Registered task reminder job"
+# "Registered overdue reminder job"
+# "Registered daily digest job"
+# "Starting worker server..."
+```
+
 ---
 
 #### 7. Set Proxy Port