chore: schedule content pipeline for Monday noon UTC (#13)

Update the default cron schedule from Sunday midnight to Monday noon UTC.

Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>

Author: kronosapiens

backend/.env.example

@@ -37,8 +37,8 @@ OHAYO_CHANNEL_ID=your_ohayo_channel_id
 
 # Content Pipeline Configuration
 # Cron schedule (optional - if not set, job won't run automatically)
-# Example: Sunday midnight UTC
-CONTENT_PIPELINE_CRON=0 0 * * 0
+# Example: Monday noon UTC
+CONTENT_PIPELINE_CRON=0 12 * * 1
 # How many days back to scan for messages
 CONTENT_PIPELINE_DAYS_BACK=7
 # Target number of stories per run