feat: Add idle detection with passive-aggressive messages

[gustafeden]

Summary

Adds idle detection that shows Haiku-generated passive-aggressive messages when the user has been inactive for 2+ minutes.

Stacked on PR #5 (feature/haiku-core-clean)

What's Included

New Files

• lib/modules/agent_network/mixins/idle_detection_mixin.dart - Timer-based idle detection mixin
• lib/modules/haiku/prompts/idle_prompt.dart - Intensity-scaled prompt builder

Modified Files

• lib/modules/agent_network/network_execution_page.dart - Mixin integration + UI display
• lib/components/attachment_text_field.dart - Added onChanged callback for idle reset

User-Visible Behavior

1. After 2 minutes of inactivity (when conversation is idle), a message appears below the input field
2. Message intensity scales with idle duration:
   • <45s: Mildly concerned
   • 45-90s: Passive-aggressive with abandonment issues
   • 90-180s: Dramatic sighing, contemplating existence

   • 180s: Full existential crisis mode

3. Message clears when user types, sends a message, or agent responds

Example Messages

• "I see you're busy. I'll just be here. Waiting. Like always."
• "Take your time. It's not like I have mass amounts of silicon at the ready."
• "Still debugging in your head, or did you forget about me?"

Test Plan

• Wait 2+ minutes with idle conversation, verify message appears
• Verify message clears when typing
• Verify message clears when sending a message
• Verify intensity increases with longer idle time

🤖 Generated with Claude Code