would be silently suppressed and never delivered to the user.

Fix

Changed .startswith(SILENT_MARKER) to == SILENT_MARKER so delivery
is only suppressed when the entire response (after stripping whitespace)
is exactly [SILENT] — matching the documented intent.

# Before (buggy)
deliver_content.strip().upper().startswith(SILENT_MARKER)

# After (fixed)
deliver_content.strip().upper() == SILENT_MARKER

Impact

• Cron reports that accidentally or intentionally start with [SILENT]
  followed by content are now correctly delivered.
• Pure [SILENT] responses (the intended use) are unaffected.

Type of Change

• 🐛 Bug fix

Checklist

• Read the Contributing Guide
• Commit messages follow Conventional Commits
• Fix matches documented system prompt intent
• No behavior change for pure [SILENT] responses